Merge remote branch 'rails/master' into identity_map

Conflicts:
	activerecord/examples/performance.rb
	activerecord/lib/active_record/association_preload.rb
	activerecord/lib/active_record/associations.rb
	activerecord/lib/active_record/associations/association_proxy.rb
	activerecord/lib/active_record/autosave_association.rb
	activerecord/lib/active_record/base.rb
	activerecord/lib/active_record/nested_attributes.rb
	activerecord/test/cases/relations_test.rb

158 files changed, 5503 insertions, 3075 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index fd571c4ca4..72bbeeec61 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,77 @@
 *Rails 3.1.0 (unreleased)*
 
+* Support the :dependent option on has_many :through associations. For historical and practical
+  reasons, :delete_all is the default deletion strategy employed by association.delete(*records),
+  despite the fact that the default strategy is :nullify for regular has_many. Also, this only
+  works at all if the source reflection is a belongs_to. For other situations, you should directly
+  modify the through association.
+
+  [Jon Leighton]
+
+* Changed the behaviour of association.destroy for has_and_belongs_to_many and has_many :through.
+  From now on, 'destroy' or 'delete' on an association will be taken to mean 'get rid of the link',
+  not (necessarily) 'get rid of the associated records'.
+
+  Previously, has_and_belongs_to_many.destroy(*records) would destroy the records themselves. It
+  would not delete any records in the join table. Now, it deletes the records in the join table.
+
+  Previously, has_many_through.destroy(*records) would destroy the records themselves, and the
+  records in the join table. [Note: This has not always been the case; previous version of Rails
+  only deleted the records themselves.] Now, it destroys only the records in the join table.
+
+  Note that this change is backwards-incompatible to an extent, but there is unfortunately no
+  way to 'deprecate' it before changing it. The change is being made in order to have
+  consistency as to the meaning of 'destroy' or 'delete' across the different types of associations.
+
+  If you wish to destroy the records themselves, you can do records.association.each(&:destroy)
+
+  [Jon Leighton]
+
+* Add :bulk => true option to change_table to make all the schema changes defined in change_table block using a single ALTER statement. [Pratik Naik]
+
+  Example:
+
+  change_table(:users, :bulk => true) do |t|
+    t.string :company_name
+    t.change :birthdate, :datetime
+  end
+
+  This will now result in:
+
+    ALTER TABLE `users` ADD COLUMN `company_name` varchar(255), CHANGE `updated_at` `updated_at` datetime DEFAULT NULL
+
+* Removed support for accessing attributes on a has_and_belongs_to_many join table. This has been
+  documented as deprecated behaviour since April 2006. Please use has_many :through instead.
+  [Jon Leighton]
+
+* Added a create_association! method for has_one and belongs_to associations. [Jon Leighton]
+
+* Migration files generated from model and constructive migration generators
+  (for example, add_name_to_users) use the reversible migration's `change`
+  method instead of the ordinary `up` and `down` methods. [Prem Sichanugrist]
+
+* Removed support for interpolating string SQL conditions on associations. Instead, you should
+  use a proc, like so:
+
+  Before:
+
+    has_many :things, :conditions => 'foo = #{bar}'
+
+  After:
+
+    has_many :things, :conditions => proc { "foo = #{bar}" }
+
+  Inside the proc, 'self' is the object which is the owner of the association, unless you are
+  eager loading the association, in which case 'self' is the class which the association is within.
+
+  You can have any "normal" conditions inside the proc, so the following will work too:
+
+    has_many :things, :conditions => proc { ["foo = ?", bar] }
+
+  Previously :insert_sql and :delete_sql on has_and_belongs_to_many association allowed you to call
+  'record' to get the record being inserted or deleted. This is now passed as an argument to
+  the proc.
+
 * Added ActiveRecord::Base#has_secure_password (via ActiveModel::SecurePassword) to encapsulate dead-simple password usage with BCrypt encryption and salting [DHH]. Example:
 
     # Schema: User(name:string, password_digest:string, password_salt:string)
@@ -19,7 +91,7 @@
     User.find_by_name("david").try(:authenticate, "mUc3m00RsqyRe") # => user
 
 
-* When a model is generated add_index is added by default for belongs_to or references columns 
+* When a model is generated add_index is added by default for belongs_to or references columns
 
   rails g model post user:belongs_to will generate the following:
 
@@ -100,7 +172,15 @@ IrreversibleMigration exception will be raised when going down.
 
   [Aaron Patterson]
 
-*Rails 3.0.2 (unreleased)*
+
+*Rails 3.0.3 (November 16, 2010)*
+
+* Support find by class like this: Post.where(:name => Post)
+
+
+*Rails 3.0.2 (November 15, 2010)*
+
+* Dramatic speed increase (see: http://engineering.attinteractive.com/2010/10/arel-two-point-ohhhhh-yaaaaaa/) [Aaron Patterson]
 
 * reorder is deprecated in favor of except(:order).order(...) [Santiago Pastorino]
 
diff --git a/activerecord/README.rdoc b/activerecord/README.rdoc
index 101a595ecd..91a23da8ad 100644
--- a/activerecord/README.rdoc
+++ b/activerecord/README.rdoc
@@ -84,7 +84,7 @@ A short rundown of some of the major features:
 
    class CommentObserver < ActiveRecord::Observer
      def after_create(comment) # is called just after Comment#save
-       Notifications.deliver_new_comment("david@loudthinking.com", comment)
+       CommentMailer.new_comment_email("david@loudthinking.com", comment)
      end
    end
 
@@ -128,7 +128,7 @@ A short rundown of some of the major features:
 
     # connect to MySQL with authentication
     ActiveRecord::Base.establish_connection(
-      :adapter  => "mysql",
+      :adapter  => "mysql2",
       :host     => "localhost",
       :username => "me",
       :password => "secret",
diff --git a/activerecord/Rakefile b/activerecord/Rakefile
index f9b77c1799..e414c4fb1c 100755
--- a/activerecord/Rakefile
+++ b/activerecord/Rakefile
@@ -41,7 +41,7 @@ namespace :test do
   end
 end
 
-%w( mysql mysql2 postgresql sqlite3 firebird db2 oracle sybase openbase frontbase jdbcmysql jdbcpostgresql jdbcsqlite3 jdbcderby jdbch2 jdbchsqldb ).each do |adapter|
+%w( mysql mysql2 postgresql sqlite3 sqlite3_mem firebird db2 oracle sybase openbase frontbase jdbcmysql jdbcpostgresql jdbcsqlite3 jdbcderby jdbch2 jdbchsqldb ).each do |adapter|
   Rake::TestTask.new("test_#{adapter}") { |t|
     connection_path = "test/connections/#{adapter =~ /jdbc/ ? 'jdbc' : 'native'}_#{adapter}"
     adapter_short = adapter == 'db2' ? adapter : adapter[/^[a-z0-9]+/]
@@ -62,7 +62,7 @@ end
     (Dir["test/cases/**/*_test.rb"].reject {
       |x| x =~ /\/adapters\//
     } + Dir["test/cases/adapters/#{adapter_short}/**/*_test.rb"]).all? do |file|
-      system(ruby, "-Ilib:test:#{connection_path}", file)
+      sh(ruby, "-Ilib:test:#{connection_path}", file)
     end or raise "Failures"
   end
 
@@ -72,6 +72,15 @@ end
   end
 end
 
+rule '.sqlite3' do |t|
+  sh %Q{sqlite3 "#{t.name}" "create table a (a integer); drop table a;"}
+end
+
+task :test_sqlite3 => [
+  'test/fixtures/fixture_database.sqlite3',
+  'test/fixtures/fixture_database_2.sqlite3'
+]
+
 namespace :mysql do
   desc 'Build the MySQL test databases'
   task :build_databases do
diff --git a/activerecord/examples/performance.rb b/activerecord/examples/performance.rb
index c97ef5b41f..22f867d783 100644
--- a/activerecord/examples/performance.rb
+++ b/activerecord/examples/performance.rb
@@ -1,31 +1,9 @@
-#!/usr/bin/env ruby -KU
-
 TIMES = (ENV['N'] || 10000).to_i
-require 'rubygems'
-
-gem 'addressable',  '~>2.0'
-gem 'faker',        '~>0.3.1'
-gem 'rbench',       '~>0.2.3'
 
-require 'addressable/uri'
-require 'faker'
-require 'rbench'
-
-require File.expand_path("../../../load_paths", __FILE__)
+require 'rubygems'
 require "active_record"
 
-conn = { :adapter => 'mysql',
-  :database => 'activerecord_unittest',
-  :username => 'rails', :password => '',
-  :encoding => 'utf8' }
-
-conn[:socket] = Pathname.glob(%w[
-  /opt/local/var/run/mysql5/mysqld.sock
-  /tmp/mysqld.sock
-  /tmp/mysql.sock
-  /var/mysql/mysql.sock
-  /var/run/mysqld/mysqld.sock
-]).find { |path| path.socket? }.to_s
+conn = { :adapter => 'sqlite3', :database => ':memory:' }
 
 ActiveRecord::Base.establish_connection(conn)
 
@@ -55,41 +33,44 @@ class Exhibit < ActiveRecord::Base
   def self.feel(exhibits) exhibits.each { |e| e.feel } end
 end
 
-sqlfile = File.expand_path("../performance.sql", __FILE__)
-
-if File.exists?(sqlfile)
-  mysql_bin = %w[mysql mysql5].detect { |bin| `which #{bin}`.length > 0 }
-  `#{mysql_bin} -u #{conn[:username]} #{"-p#{conn[:password]}" unless conn[:password].blank?} #{conn[:database]} < #{sqlfile}`
-else
-  puts 'Generating data...'
-
-  # pre-compute the insert statements and fake data compilation,
-  # so the benchmarks below show the actual runtime for the execute
-  # method, minus the setup steps
-
-  # Using the same paragraph for all exhibits because it is very slow
-  # to generate unique paragraphs for all exhibits.
-  notes = Faker::Lorem.paragraphs.join($/)
-  today = Date.today
-
-  puts 'Inserting 10,000 users and exhibits...'
-  10_000.times do
-    user = User.create(
-      :created_at => today,
-      :name       => Faker::Name.name,
-      :email      => Faker::Internet.email
-    )
-
-    Exhibit.create(
-      :created_at => today,
-      :name       => Faker::Company.name,
-      :user       => user,
-      :notes      => notes
-    )
-  end
-
-  mysqldump_bin = %w[mysqldump mysqldump5].detect { |bin| `which #{bin}`.length > 0 }
-  `#{mysqldump_bin} -u #{conn[:username]} #{"-p#{conn[:password]}" unless conn[:password].blank?} #{conn[:database]} exhibits users > #{sqlfile}`
+puts 'Generating data...'
+
+module ActiveRecord
+  class Faker
+    LOREM = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse non aliquet diam. Curabitur vel urna metus, quis malesuada elit. Integer consequat tincidunt felis. Etiam non erat dolor. Vivamus imperdiet nibh sit amet diam eleifend id posuere diam malesuada. Mauris at accumsan sem. Donec id lorem neque. Fusce erat lorem, ornare eu congue vitae, malesuada quis neque. Maecenas vel urna a velit pretium fermentum. Donec tortor enim, tempor venenatis egestas a, tempor sed ipsum. Ut arcu justo, faucibus non imperdiet ac, interdum at diam. Pellentesque ipsum enim, venenatis ut iaculis vitae, varius vitae sem. Sed rutrum quam ac elit euismod bibendum. Donec ultricies ultricies magna, at lacinia libero mollis aliquam. Sed ac arcu in tortor elementum tincidunt vel interdum sem. Curabitur eget erat arcu. Praesent eget eros leo. Nam magna enim, sollicitudin vehicula scelerisque in, vulputate ut libero. Praesent varius tincidunt commodo".split
+    def self.name
+      LOREM.grep(/^\w*$/).sort_by { rand }.first(2).join ' '
+    end
+
+    def self.email
+      LOREM.grep(/^\w*$/).sort_by { rand }.first(2).join('@') + ".com"
+    end
+  end
+end
+
+# pre-compute the insert statements and fake data compilation,
+# so the benchmarks below show the actual runtime for the execute
+# method, minus the setup steps
+
+# Using the same paragraph for all exhibits because it is very slow
+# to generate unique paragraphs for all exhibits.
+notes = ActiveRecord::Faker::LOREM.join ' '
+today = Date.today
+
+puts 'Inserting 10,000 users and exhibits...'
+10_000.times do
+  user = User.create(
+    :created_at => today,
+    :name       => ActiveRecord::Faker.name,
+    :email      => ActiveRecord::Faker.email
+  )
+
+  Exhibit.create(
+    :created_at => today,
+    :name       => ActiveRecord::Faker.name,
+    :user       => user,
+    :notes      => notes
+  )
 end
 
 ActiveRecord::IdentityMap.enabled = true unless ENV['IM'] == "disabled"
@@ -98,102 +79,87 @@ def clear_identity_map!
   ActiveRecord::IdentityMap.clear
 end
 
-RBench.run(TIMES) do
-  column :times
-  column :ar
-
-
-  report 'Model#id', (TIMES * 100).ceil do
-    ar_obj = Exhibit.find(1)
+require 'benchmark'
+
+Benchmark.bm(46) do |x|
+  clear_identity_map!
+  ar_obj       = Exhibit.find(1)
+  attrs        = { :name => 'sam' }
+  attrs_first  = { :name => 'sam' }
+  attrs_second = { :name => 'tom' }
+  exhibit      = {
+    :name       => ActiveRecord::Faker.name,
+    :notes      => notes,
+    :created_at => Date.today
+  }
 
-    ar { ar_obj.id }
+  x.report("Model#id (x#{(TIMES * 100).ceil})") do
+    (TIMES * 100).ceil.times { ar_obj.id }
   end
 
-  report 'Model.new (instantiation)' do
-    ar { Exhibit.new }
+  x.report 'Model.new (instantiation)' do
+    TIMES.times { Exhibit.new }
   end
 
-  report 'Model.new (setting attributes)' do
-    attrs = { :name => 'sam' }
-    ar { Exhibit.new(attrs) }
+  x.report 'Model.new (setting attributes)' do
+    TIMES.times { Exhibit.new(attrs) }
   end
 
-  report 'Model.first' do
-    clear_identity_map!
-    ar { Exhibit.first.look }
+  x.report 'Model.first' do
+    TIMES.times { Exhibit.first.look }
   end
 
-  report 'Model.all limit(100)', (TIMES / 10).ceil do
-    clear_identity_map!
-    ar { Exhibit.look Exhibit.limit(100) }
+  x.report("Model.all limit(100) (x#{(TIMES / 10).ceil})") do
+    (TIMES / 10).ceil.times { Exhibit.look Exhibit.limit(100) }
   end
 
-  report 'Model.all limit(100) with relationship', (TIMES / 10).ceil do
-    clear_identity_map!
-    ar { Exhibit.feel Exhibit.limit(100).includes(:user) }
+  x.report "Model.all limit(100) with relationship (x#{(TIMES / 10).ceil})" do
+    (TIMES / 10).ceil.times { Exhibit.feel Exhibit.limit(100).includes(:user) }
   end
 
-  report 'Model.all limit(10,000)', (TIMES / 1000).ceil do
-    clear_identity_map!
-    ar { Exhibit.look Exhibit.limit(10000) }
+  x.report "Model.all limit(10,000) x(#{(TIMES / 1000).ceil})" do
+    (TIMES / 1000).ceil.times { Exhibit.look Exhibit.limit(10000) }
   end
 
-  exhibit = {
-    :name       => Faker::Company.name,
-    :notes      => Faker::Lorem.paragraphs.join($/),
-    :created_at => Date.today
-  }
-
-  report 'Model.create' do
-    clear_identity_map!
-    ar { Exhibit.create(exhibit) }
+  x.report 'Model.create' do
+    TIMES.times { Exhibit.create(exhibit) }
   end
 
-  report 'Resource#attributes=' do
-    clear_identity_map!
-    attrs_first  = { :name => 'sam' }
-    attrs_second = { :name => 'tom' }
-    ar { exhibit = Exhibit.new(attrs_first); exhibit.attributes = attrs_second }
+  x.report 'Resource#attributes=' do
+    TIMES.times {
+      exhibit = Exhibit.new(attrs_first)
+      exhibit.attributes = attrs_second
+    }
   end
 
-  report 'Resource#update' do
-    clear_identity_map!
-    ar { Exhibit.first.update_attributes(:name => 'bob') }
+  x.report 'Resource#update' do
+    TIMES.times { Exhibit.first.update_attributes(:name => 'bob') }
   end
 
-  report 'Resource#destroy' do
-    clear_identity_map!
-    ar { Exhibit.first.destroy }
+  x.report 'Resource#destroy' do
+    TIMES.times { Exhibit.first.destroy }
   end
 
-  report 'Model.transaction' do
-    clear_identity_map!
-    ar { Exhibit.transaction { Exhibit.new } }
+  x.report 'Model.transaction' do
+    TIMES.times { Exhibit.transaction { Exhibit.new } }
   end
 
-  report 'Model.find(id)' do
-    clear_identity_map!
+  x.report 'Model.find(id)' do
     id = Exhibit.first.id
-    ar { Exhibit.find(id) }
+    TIMES.times { Exhibit.find(id) }
   end
 
-  report 'Model.find_by_sql' do
-    clear_identity_map!
-    ar { Exhibit.find_by_sql("SELECT * FROM exhibits WHERE id = #{(rand * 1000 + 1).to_i}").first }
+  x.report 'Model.find_by_sql' do
+    TIMES.times {
+      Exhibit.find_by_sql("SELECT * FROM exhibits WHERE id = #{(rand * 1000 + 1).to_i}").first
+    }
   end
 
-  report 'Model.log', (TIMES * 10) do
-    clear_identity_map!
-    ar { Exhibit.connection.send(:log, "hello", "world") {} }
+  x.report "Model.log x(#{TIMES * 10})" do
+    (TIMES * 10).times { Exhibit.connection.send(:log, "hello", "world") {} }
   end
 
-  report 'AR.execute(query)', (TIMES / 2) do
-    clear_identity_map!
-    ar { ActiveRecord::Base.connection.execute("Select * from exhibits where id = #{(rand * 1000 + 1).to_i}") }
+  x.report "AR.execute(query) (#{TIMES / 2})" do
+    (TIMES / 2).times { ActiveRecord::Base.connection.execute("Select * from exhibits where id = #{(rand * 1000 + 1).to_i}") }
   end
-
-  summary 'Total'
 end
-
-ActiveRecord::Migration.drop_table "exhibits"
-ActiveRecord::Migration.drop_table "users"
diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 83e20af3d0..8379f6a66f 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -82,6 +82,10 @@ module ActiveRecord
     autoload :IdentityMap
   end
 
+  module Coders
+    autoload :YAMLColumn, 'active_record/coders/yaml_column'
+  end
+
   module AttributeMethods
     extend ActiveSupport::Autoload
 
diff --git a/activerecord/lib/active_record/aggregations.rb b/activerecord/lib/active_record/aggregations.rb
index 8cd7389005..90d3b58c78 100644
--- a/activerecord/lib/active_record/aggregations.rb
+++ b/activerecord/lib/active_record/aggregations.rb
@@ -4,9 +4,7 @@ module ActiveRecord
     extend ActiveSupport::Concern
 
     def clear_aggregation_cache #:nodoc:
-      self.class.reflect_on_all_aggregations.to_a.each do |assoc|
-        instance_variable_set "@#{assoc.name}", nil
-      end if self.persisted?
+      @aggregation_cache.clear if persisted?
     end
 
     # Active Record implements aggregation through a macro-like class method called +composed_of+
@@ -222,53 +220,32 @@ module ActiveRecord
 
       private
         def reader_method(name, class_name, mapping, allow_nil, constructor)
-          module_eval do
-            define_method(name) do |*args|
-              force_reload = args.first || false
-
-              unless instance_variable_defined?("@#{name}")
-                instance_variable_set("@#{name}", nil)
-              end
-
-              if (instance_variable_get("@#{name}").nil? || force_reload) && (!allow_nil || mapping.any? {|pair| !read_attribute(pair.first).nil? })
-                attrs = mapping.collect {|pair| read_attribute(pair.first)}
-                object = case constructor
-                  when Symbol
-                    class_name.constantize.send(constructor, *attrs)
-                  when Proc, Method
-                    constructor.call(*attrs)
-                  else
-                    raise ArgumentError, 'Constructor must be a symbol denoting the constructor method to call or a Proc to be invoked.'
-                  end
-                instance_variable_set("@#{name}", object)
-              end
-              instance_variable_get("@#{name}")
+          define_method(name) do
+            if @aggregation_cache[name].nil? && (!allow_nil || mapping.any? {|pair| !read_attribute(pair.first).nil? })
+              attrs = mapping.collect {|pair| read_attribute(pair.first)}
+              object = constructor.respond_to?(:call) ?
+                constructor.call(*attrs) :
+                class_name.constantize.send(constructor, *attrs)
+              @aggregation_cache[name] = object
             end
+            @aggregation_cache[name]
           end
-
         end
 
         def writer_method(name, class_name, mapping, allow_nil, converter)
-          module_eval do
-            define_method("#{name}=") do |part|
-              if part.nil? && allow_nil
-                mapping.each { |pair| self[pair.first] = nil }
-                instance_variable_set("@#{name}", nil)
-              else
-                unless part.is_a?(class_name.constantize) || converter.nil?
-                  part = case converter
-                    when Symbol
-                     class_name.constantize.send(converter, part)
-                    when Proc, Method
-                      converter.call(part)
-                    else
-                      raise ArgumentError, 'Converter must be a symbol denoting the converter method to call or a Proc to be invoked.'
-                    end
-                end
-
-                mapping.each { |pair| self[pair.first] = part.send(pair.last) }
-                instance_variable_set("@#{name}", part.freeze)
+          define_method("#{name}=") do |part|
+            if part.nil? && allow_nil
+              mapping.each { |pair| self[pair.first] = nil }
+              @aggregation_cache[name] = nil
+            else
+              unless part.is_a?(class_name.constantize) || converter.nil?
+                part = converter.respond_to?(:call) ?
+                  converter.call(part) :
+                  class_name.constantize.send(converter, part)
               end
+
+              mapping.each { |pair| self[pair.first] = part.send(pair.last) }
+              @aggregation_cache[name] = part.freeze
             end
           end
         end
diff --git a/activerecord/lib/active_record/association_preload.rb b/activerecord/lib/active_record/association_preload.rb
index 373532704f..52d2c49836 100644
--- a/activerecord/lib/active_record/association_preload.rb
+++ b/activerecord/lib/active_record/association_preload.rb
@@ -125,45 +125,48 @@ module ActiveRecord
       def add_preloaded_records_to_collection(parent_records, reflection_name, associated_record)
         parent_records.each do |parent_record|
           association_proxy = parent_record.send(reflection_name)
-          association_proxy.loaded
-          association_proxy.target = association_proxy.target | [*Array.wrap(associated_record)]
-
-          association_proxy.__send__(:set_inverse_instance, associated_record, parent_record)
+          association_proxy.loaded!
+          association_proxy.target.concat(Array.wrap(associated_record))
+          association_proxy.send(:set_inverse_instance, associated_record)
         end
       end
 
       def add_preloaded_record_to_collection(parent_records, reflection_name, associated_record)
         parent_records.each do |parent_record|
-          parent_record.send("set_#{reflection_name}_target", associated_record)
+          parent_record.send(:association_proxy, reflection_name).target = associated_record
         end
       end
 
-      def set_association_collection_records(id_to_record_map, reflection_name, associated_records, key)
+      def set_association_collection_records(id_to_parent_map, reflection_name, associated_records, key)
         associated_records.each do |associated_record|
-          mapped_records = id_to_record_map[associated_record[key].to_s]
-          add_preloaded_records_to_collection(mapped_records, reflection_name, associated_record)
+          parent_records = id_to_parent_map[associated_record[key].to_s]
+          add_preloaded_records_to_collection(parent_records, reflection_name, associated_record)
         end
       end
 
       def set_association_single_records(id_to_record_map, reflection_name, associated_records, key)
         seen_keys = {}
         associated_records.each do |associated_record|
+          seen_key = associated_record[key].to_s
+
           #this is a has_one or belongs_to: there should only be one record.
           #Unfortunately we can't (in portable way) ask the database for
           #'all records where foo_id in (x,y,z), but please
           # only one row per distinct foo_id' so this where we enforce that
-          next if seen_keys[associated_record[key].to_s]
-          seen_keys[associated_record[key].to_s] = true
-          mapped_records = id_to_record_map[associated_record[key].to_s]
+          next if seen_keys.key? seen_key
+
+          seen_keys[seen_key] = true
+          mapped_records = id_to_record_map[seen_key]
           mapped_records.each do |mapped_record|
-            association_proxy = mapped_record.send("set_#{reflection_name}_target", associated_record)
-            association_proxy.__send__(:set_inverse_instance, associated_record, mapped_record)
+            association_proxy = mapped_record.send(:association_proxy, reflection_name)
+            association_proxy.target = associated_record
+            association_proxy.send(:set_inverse_instance, associated_record)
           end
         end
 
         id_to_record_map.each do |id, records|
-          next if seen_keys.include?(id.to_s)
-          records.each {|record| record.send("set_#{reflection_name}_target", nil) }
+          next if seen_keys.include?(id)
+          add_preloaded_record_to_collection(records, reflection_name, nil)
         end
       end
 
@@ -172,57 +175,80 @@ module ActiveRecord
       # <tt>(id_to_record_map, ids)</tt> where +id_to_record_map+ is the Hash,
       # and +ids+ is an Array of record IDs.
       def construct_id_map(records, primary_key=nil)
-        id_to_record_map = {}
-        ids = []
-        records.each do |record|
+        records.group_by do |record|
           primary_key ||= record.class.primary_key
-          ids << record[primary_key]
-          mapped_records = (id_to_record_map[ids.last.to_s] ||= [])
-          mapped_records << record
+          record[primary_key].to_s
         end
-        ids.uniq!
-        return id_to_record_map, ids
       end
 
       def preload_has_and_belongs_to_many_association(records, reflection, preload_options={})
-        table_name = reflection.klass.quoted_table_name
-        id_to_record_map, ids = construct_id_map(records)
-        records.each {|record| record.send(reflection.name).loaded}
+
+        left = reflection.klass.arel_table
+
+        id_to_record_map = construct_id_map(records)
+
+        records.each { |record| record.send(reflection.name).loaded! }
         options = reflection.options
 
-        conditions = "t0.#{reflection.primary_key_name} #{in_or_equals_for_ids(ids)}"
-        conditions << append_conditions(reflection, preload_options)
+        right = Arel::Table.new(options[:join_table]).alias('t0')
+
+        join_condition = left[reflection.klass.primary_key].eq(
+          right[reflection.association_foreign_key])
+
+        join = left.create_join(right, left.create_on(join_condition))
+        select = [
+          # FIXME: options[:select] is always nil in the tests.  Do we really
+          # need it?
+          options[:select] || left[Arel.star],
+          right[reflection.foreign_key].as(
+            Arel.sql('the_parent_record_id'))
+        ]
 
         associated_records_proxy = reflection.klass.unscoped.
             includes(options[:include]).
-            joins("INNER JOIN #{connection.quote_table_name options[:join_table]} t0 ON #{reflection.klass.quoted_table_name}.#{reflection.klass.primary_key} = t0.#{reflection.association_foreign_key}").
-            select("#{options[:select] || table_name+'.*'}, t0.#{reflection.primary_key_name} as the_parent_record_id").
             order(options[:order])
 
-        all_associated_records = ActiveRecord::IdentityMap.without do
-          associated_records(ids) do |some_ids|
-            associated_records_proxy.where([conditions, ids]).to_a
-          end
-        end
+        associated_records_proxy.joins_values = [join]
+        associated_records_proxy.select_values = select
+
+        custom_conditions = append_conditions(reflection, preload_options)
+
+        klass = associated_records_proxy.klass
 
-        set_association_collection_records(id_to_record_map, reflection.name, all_associated_records, 'the_parent_record_id')
+        associated_records(id_to_record_map.keys) { |some_ids|
+          method     = in_or_equal(some_ids)
+          conditions = right.create_and(
+            [right[reflection.foreign_key].send(*method)] +
+            custom_conditions)
+
+          relation = associated_records_proxy.where(conditions)
+          klass.connection.select_all(relation.arel.to_sql, 'SQL', relation.bind_values)
+        }.map! { |row|
+          parent_records = id_to_record_map[row['the_parent_record_id'].to_s]
+          associated_record = klass.instantiate row
+          add_preloaded_records_to_collection(
+            parent_records, reflection.name, associated_record)
+          associated_record
+        }
       end
 
       def preload_has_one_association(records, reflection, preload_options={})
-        return if records.first.send("loaded_#{reflection.name}?")
-        id_to_record_map, ids = construct_id_map(records, reflection.options[:primary_key])
+        return if records.first.send(:association_proxy, reflection.name).loaded?
+        id_to_record_map = construct_id_map(records, reflection.options[:primary_key])
         options = reflection.options
-        records.each {|record| record.send("set_#{reflection.name}_target", nil)}
+
+        add_preloaded_record_to_collection(records, reflection.name, nil)
+
         if options[:through]
           through_records = preload_through_records(records, reflection, options[:through])
 
           unless through_records.empty?
             through_reflection = reflections[options[:through]]
-            through_primary_key = through_reflection.primary_key_name
+            through_primary_key = through_reflection.foreign_key
             source = reflection.source_reflection.name
             through_records.first.class.preload_associations(through_records, source)
             if through_reflection.macro == :belongs_to
-              id_to_record_map    = construct_id_map(records, through_primary_key).first
+              id_to_record_map    = construct_id_map(records, through_primary_key)
               through_primary_key = through_reflection.klass.primary_key
             end
 
@@ -232,7 +258,7 @@ module ActiveRecord
             end
           end
         else
-          set_association_single_records(id_to_record_map, reflection.name, find_associated_records(ids, reflection, preload_options), reflection.primary_key_name)
+          set_association_single_records(id_to_record_map, reflection.name, find_associated_records(id_to_record_map.keys, reflection, preload_options), reflection.foreign_key)
         end
       end
 
@@ -240,9 +266,9 @@ module ActiveRecord
         return if records.first.send(reflection.name).loaded?
         options = reflection.options
 
-        primary_key_name = reflection.through_reflection_primary_key_name
-        id_to_record_map, ids = construct_id_map(records, primary_key_name || reflection.options[:primary_key])
-        records.each {|record| record.send(reflection.name).loaded}
+        foreign_key = reflection.through_reflection_foreign_key
+        id_to_record_map = construct_id_map(records, foreign_key || reflection.options[:primary_key])
+        records.each { |record| record.send(reflection.name).loaded! }
 
         if options[:through]
           through_records = preload_through_records(records, reflection, options[:through])
@@ -257,14 +283,14 @@ module ActiveRecord
           end
 
         else
-          set_association_collection_records(id_to_record_map, reflection.name, find_associated_records(ids, reflection, preload_options),
-                                             reflection.primary_key_name)
+          set_association_collection_records(id_to_record_map, reflection.name, find_associated_records(id_to_record_map.keys, reflection, preload_options),
+                                             reflection.foreign_key)
         end
       end
 
       def preload_through_records(records, reflection, through_association)
         if reflection.options[:source_type]
-          interface = reflection.source_reflection.options[:foreign_type]
+          interface = reflection.source_reflection.foreign_type
           preload_options = {:conditions => ["#{connection.quote_column_name interface} = ?", reflection.options[:source_type]]}
 
           records.compact!
@@ -294,76 +320,71 @@ module ActiveRecord
       end
 
       def preload_belongs_to_association(records, reflection, preload_options={})
-        return if records.first.send("loaded_#{reflection.name}?")
+        return if records.first.send(:association_proxy, reflection.name).loaded?
         options = reflection.options
-        primary_key_name = reflection.primary_key_name
 
         klasses_and_ids = {}
 
         if options[:polymorphic]
-          polymorph_type = options[:foreign_type]
-
           # Construct a mapping from klass to a list of ids to load and a mapping of those ids back
           # to their parent_records
           records.each do |record|
-            if klass = record.send(polymorph_type)
-              klass_id = record.send(primary_key_name)
+            if klass = record.send(reflection.foreign_type)
+              klass_id = record.send(reflection.foreign_key)
               if klass_id
-                id_map = klasses_and_ids[klass] ||= {}
+                id_map = klasses_and_ids[klass.constantize] ||= {}
                 (id_map[klass_id.to_s] ||= []) << record
               end
             end
           end
         else
-          id_map = {}
-          records.each do |record|
-            key = record.send(primary_key_name)
-            (id_map[key.to_s] ||= []) << record if key
+          id_map = records.group_by do |record|
+            key = record.send(reflection.foreign_key)
+            key && key.to_s
           end
-          klasses_and_ids[reflection.klass.name] = id_map unless id_map.empty?
+          klasses_and_ids[reflection.klass] = id_map unless id_map.empty?
         end
 
-        klasses_and_ids.each do |klass_name, _id_map|
-          klass = klass_name.constantize
-
-          table_name = klass.quoted_table_name
+        klasses_and_ids.each do |klass, _id_map|
           primary_key = (reflection.options[:primary_key] || klass.primary_key).to_s
-          column_type = klass.columns.detect{|c| c.name == primary_key}.type
-
-          ids = _id_map.keys.map do |id|
-            if column_type == :integer
-              id.to_i
-            elsif column_type == :float
-              id.to_f
-            else
-              id
-            end
-          end
+          keys        = _id_map.keys.compact
 
-          conditions = "#{table_name}.#{connection.quote_column_name(primary_key)} #{in_or_equals_for_ids(ids)}"
-          conditions << append_conditions(reflection, preload_options)
+          unless keys.empty?
+            table       = klass.arel_table
+            method      = in_or_equal(keys)
+            conditions  = table[primary_key].send(*method)
 
-          associated_records = klass.unscoped.where([conditions, ids]).apply_finder_options(options.slice(:include, :select, :joins, :order)).to_a
+            custom_conditions = append_conditions(reflection, preload_options)
+            conditions = custom_conditions.inject(conditions) do |ast, cond|
+              ast.and cond
+            end
+
+            associated_records = klass.unscoped.where(conditions).apply_finder_options(options.slice(:include, :select, :joins, :order)).to_a
+          else
+            associated_records = []
+          end
 
           set_association_single_records(_id_map, reflection.name, associated_records, primary_key)
         end
       end
 
       def find_associated_records(ids, reflection, preload_options)
-        options = reflection.options
-        table_name = reflection.klass.quoted_table_name
+        options    = reflection.options
+        table      = reflection.klass.arel_table
+
+        conditions = []
+
+        key = reflection.foreign_key
 
         if interface = reflection.options[:as]
-          conditions = "#{reflection.klass.quoted_table_name}.#{connection.quote_column_name "#{interface}_id"} #{in_or_equals_for_ids(ids)} and #{reflection.klass.quoted_table_name}.#{connection.quote_column_name "#{interface}_type"} = '#{self.base_class.sti_name}'"
-        else
-          foreign_key = reflection.primary_key_name
-          conditions = "#{reflection.klass.quoted_table_name}.#{foreign_key} #{in_or_equals_for_ids(ids)}"
+          key = "#{interface}_id"
+          conditions << table["#{interface}_type"].eq(base_class.sti_name)
         end
 
-        conditions << append_conditions(reflection, preload_options)
+        conditions.concat append_conditions(reflection, preload_options)
 
         find_options = {
-          :select => preload_options[:select] || options[:select] || Arel::SqlLiteral.new("#{table_name}.*"),
+          :select => preload_options[:select] || options[:select] || table[Arel.star],
           :include => preload_options[:include] || options[:include],
           :joins => options[:joins],
           :group => preload_options[:group] || options[:group],
@@ -371,24 +392,30 @@ module ActiveRecord
         }
 
         associated_records(ids) do |some_ids|
-          reflection.klass.scoped.apply_finder_options(find_options.merge(:conditions => [conditions, some_ids])).to_a
+          method = in_or_equal(some_ids)
+          where = table.create_and(conditions + [table[key].send(*method)])
+
+          reflection.klass.scoped.apply_finder_options(find_options.merge(:conditions => where)).to_a
         end
       end
 
+      def process_conditions(conditions, klass = self)
+        if conditions.respond_to?(:to_proc)
+          conditions = instance_eval(&conditions)
+        end
 
-      def interpolate_sql_for_preload(sql)
-        instance_eval("%@#{sql.gsub('@', '\@')}@", __FILE__, __LINE__)
+        klass.send(:sanitize_sql, conditions)
       end
 
       def append_conditions(reflection, preload_options)
-        sql = ""
-        sql << " AND (#{interpolate_sql_for_preload(reflection.sanitized_conditions)})" if reflection.sanitized_conditions
-        sql << " AND (#{sanitize_sql preload_options[:conditions]})" if preload_options[:conditions]
-        sql
+        [
+          ('(' + process_conditions(reflection.options[:conditions], reflection.klass) + ')' if reflection.options[:conditions]),
+          ('(' + process_conditions(preload_options[:conditions]) + ')' if preload_options[:conditions]),
+        ].compact.map { |x| Arel.sql x }
       end
 
-      def in_or_equals_for_ids(ids)
-        ids.size > 1 ? "IN (?)" : "= ?"
+      def in_or_equal(ids)
+        ids.length == 1 ? ['eq', ids.first] : ['in', ids]
       end
 
       # Some databases impose a limit on the number of ids in a list (in Oracle its 1000)
@@ -397,7 +424,7 @@ module ActiveRecord
         in_clause_length = connection.in_clause_length || ids.size
         records = []
         ids.each_slice(in_clause_length) do |some_ids|
-          records += yield(some_ids)
+          records.concat yield(some_ids)
         end
         records
       end
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 371dad9104..a2db592c7d 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -20,18 +20,30 @@ module ActiveRecord
     end
   end
 
-  class HasManyThroughAssociationPolymorphicError < ActiveRecordError #:nodoc:
+  class HasManyThroughAssociationPolymorphicSourceError < ActiveRecordError #:nodoc:
     def initialize(owner_class_name, reflection, source_reflection)
       super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' on the polymorphic object '#{source_reflection.class_name}##{source_reflection.name}'.")
     end
   end
 
+  class HasManyThroughAssociationPolymorphicThroughError < ActiveRecordError #:nodoc:
+    def initialize(owner_class_name, reflection)
+      super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' which goes through the polymorphic association '#{owner_class_name}##{reflection.through_reflection.name}'.")
+    end
+  end
+
   class HasManyThroughAssociationPointlessSourceTypeError < ActiveRecordError #:nodoc:
     def initialize(owner_class_name, reflection, source_reflection)
       super("Cannot have a has_many :through association '#{owner_class_name}##{reflection.name}' with a :source_type option if the '#{reflection.through_reflection.class_name}##{source_reflection.name}' is not polymorphic.  Try removing :source_type on your association.")
     end
   end
 
+  class HasOneThroughCantAssociateThroughCollection < ActiveRecordError #:nodoc:
+    def initialize(owner_class_name, reflection, through_reflection)
+      super("Cannot have a has_one :through association '#{owner_class_name}##{reflection.name}' where the :through association '#{owner_class_name}##{through_reflection.name}' is a collection. Specify a has_one or belongs_to association in the :through option instead.")
+    end
+  end
+
   class HasManyThroughSourceAssociationNotFoundError < ActiveRecordError #:nodoc:
     def initialize(reflection)
       through_reflection      = reflection.through_reflection
@@ -107,7 +119,9 @@ module ActiveRecord
     # These classes will be loaded when associations are created.
     # So there is no need to eager load them.
     autoload :AssociationCollection, 'active_record/associations/association_collection'
+    autoload :SingularAssociation, 'active_record/associations/singular_association'
     autoload :AssociationProxy, 'active_record/associations/association_proxy'
+    autoload :ThroughAssociation, 'active_record/associations/through_association'
     autoload :BelongsToAssociation, 'active_record/associations/belongs_to_association'
     autoload :BelongsToPolymorphicAssociation, 'active_record/associations/belongs_to_polymorphic_association'
     autoload :HasAndBelongsToManyAssociation, 'active_record/associations/has_and_belongs_to_many_association'
@@ -118,30 +132,40 @@ module ActiveRecord
 
     # Clears out the association cache.
     def clear_association_cache #:nodoc:
-      self.class.reflect_on_all_associations.to_a.each do |assoc|
-        if IdentityMap.enabled? && instance_variable_defined?("@#{assoc.name}")
-          Array(instance_variable_get("@#{assoc.name}")).each do |t|
-            next unless t.respond_to?(:target)
-            IdentityMap.remove t.target unless t.target.nil?
-          end
-        end
-        instance_variable_set "@#{assoc.name}", nil
-      end if self.persisted?
+      @association_cache.clear if persisted?
     end
 
+    # :nodoc:
+    attr_reader :association_cache
+
+    protected
+
+      # Returns the proxy for the given association name, instantiating it if it doesn't
+      # already exist
+      def association_proxy(name)
+        association = association_instance_get(name)
+
+        if association.nil?
+          reflection  = self.class.reflect_on_association(name)
+          association = reflection.proxy_class.new(self, reflection)
+          association_instance_set(name, association)
+        end
+
+        association
+      end
+
     private
       # Returns the specified association instance if it responds to :loaded?, nil otherwise.
       def association_instance_get(name)
-        ivar = "@#{name}"
-        if instance_variable_defined?(ivar)
-          association = instance_variable_get(ivar)
+        if @association_cache.key? name
+          association = @association_cache[name]
           association if association.respond_to?(:loaded?)
         end
       end
 
       # Set the specified association instance.
       def association_instance_set(name, association)
-        instance_variable_set("@#{name}", association)
+        @association_cache[name] = association
       end
 
     # Associations are a set of macro-like class methods for tying objects together through
@@ -185,7 +209,7 @@ module ActiveRecord
     #   other=(other)                     |     X      |      X       |    X
     #   build_other(attributes={})        |     X      |              |    X
     #   create_other(attributes={})       |     X      |              |    X
-    #   other.create!(attributes={})      |            |              |    X
+    #   create_other!(attributes={})      |     X      |              |    X
     #
     # ===Collection associations (one-to-many / many-to-many)
     #                                     |       |          | has_many
@@ -208,10 +232,9 @@ module ActiveRecord
     #   others.empty?                     |   X   |    X     |    X
     #   others.clear                      |   X   |    X     |    X
     #   others.delete(other,other,...)    |   X   |    X     |    X
-    #   others.delete_all                 |   X   |    X     |
+    #   others.delete_all                 |   X   |    X     |    X
     #   others.destroy_all                |   X   |    X     |    X
     #   others.find(*args)                |   X   |    X     |    X
-    #   others.find_first                 |   X   |          |
     #   others.exists?                    |   X   |    X     |    X
     #   others.uniq                       |   X   |    X     |    X
     #   others.reset                      |   X   |    X     |    X
@@ -325,26 +348,31 @@ module ActiveRecord
     # === One-to-one associations
     #
     # * Assigning an object to a +has_one+ association automatically saves that object and
-    # the object being replaced (if there is one), in order to update their primary
-    # keys - except if the parent object is unsaved (<tt>new_record? == true</tt>).
-    # * If either of these saves fail (due to one of the objects being invalid) the assignment
-    # statement returns +false+ and the assignment is cancelled.
+    #   the object being replaced (if there is one), in order to update their foreign
+    #   keys - except if the parent object is unsaved (<tt>new_record? == true</tt>).
+    # * If either of these saves fail (due to one of the objects being invalid), an
+    #   <tt>ActiveRecord::RecordNotSaved</tt> exception is raised and the assignment is
+    #   cancelled.
     # * If you wish to assign an object to a +has_one+ association without saving it,
-    # use the <tt>association.build</tt> method (documented below).
+    #   use the <tt>build_association</tt> method (documented below). The object being
+    #   replaced will still be saved to update its foreign key.
     # * Assigning an object to a +belongs_to+ association does not save the object, since
-    # the foreign key field belongs on the parent. It does not save the parent either.
+    #   the foreign key field belongs on the parent. It does not save the parent either.
     #
     # === Collections
     #
     # * Adding an object to a collection (+has_many+ or +has_and_belongs_to_many+) automatically
-    # saves that object, except if the parent object (the owner of the collection) is not yet
-    # stored in the database.
+    #   saves that object, except if the parent object (the owner of the collection) is not yet
+    #   stored in the database.
     # * If saving any of the objects being added to a collection (via <tt>push</tt> or similar)
-    # fails, then <tt>push</tt> returns +false+.
+    #   fails, then <tt>push</tt> returns +false+.
+    # * If saving fails while replacing the collection (via <tt>association=</tt>), an
+    #   <tt>ActiveRecord::RecordNotSaved</tt> exception is raised and the assignment is
+    #   cancelled.
     # * You can add an object to a collection without automatically saving it by using the
-    # <tt>collection.build</tt> method (documented below).
+    #   <tt>collection.build</tt> method (documented below).
     # * All unsaved (<tt>new_record? == true</tt>) members of the collection are automatically
-    # saved when the parent is saved.
+    #   saved when the parent is saved.
     #
     # === Association callbacks
     #
@@ -804,6 +832,73 @@ module ActiveRecord
     # * does not work with <tt>:polymorphic</tt> associations.
     # * for +belongs_to+ associations +has_many+ inverse associations are ignored.
     #
+    # == Deleting from associations
+    #
+    # === Dependent associations
+    #
+    # +has_many+, +has_one+ and +belongs_to+ associations support the <tt>:dependent</tt> option.
+    # This allows you to specify that associated records should be deleted when the owner is
+    # deleted.
+    #
+    # For example:
+    #
+    #     class Author
+    #       has_many :posts, :dependent => :destroy
+    #     end
+    #     Author.find(1).destroy # => Will destroy all of the author's posts, too
+    #
+    # The <tt>:dependent</tt> option can have different values which specify how the deletion
+    # is done. For more information, see the documentation for this option on the different
+    # specific association types.
+    #
+    # === Delete or destroy?
+    #
+    # +has_many+ and +has_and_belongs_to_many+ associations have the methods <tt>destroy</tt>,
+    # <tt>delete</tt>, <tt>destroy_all</tt> and <tt>delete_all</tt>.
+    #
+    # For +has_and_belongs_to_many+, <tt>delete</tt> and <tt>destroy</tt> are the same: they
+    # cause the records in the join table to be removed.
+    #
+    # For +has_many+, <tt>destroy</tt> will always call the <tt>destroy</tt> method of the
+    # record(s) being removed so that callbacks are run. However <tt>delete</tt> will either
+    # do the deletion according to the strategy specified by the <tt>:dependent</tt> option, or
+    # if no <tt>:dependent</tt> option is given, then it will follow the default strategy.
+    # The default strategy is <tt>:nullify</tt> (set the foreign keys to <tt>nil</tt>), except for
+    # +has_many+ <tt>:through</tt>, where the default strategy is <tt>delete_all</tt> (delete
+    # the join records, without running their callbacks).
+    #
+    # There is also a <tt>clear</tt> method which is the same as <tt>delete_all</tt>, except that
+    # it returns the association rather than the records which have been deleted.
+    #
+    # === What gets deleted?
+    #
+    # There is a potential pitfall here: +has_and_belongs_to_many+ and +has_many+ <tt>:through</tt>
+    # associations have records in join tables, as well as the associated records. So when we
+    # call one of these deletion methods, what exactly should be deleted?
+    #
+    # The answer is that it is assumed that deletion on an association is about removing the
+    # <i>link</i> between the owner and the associated object(s), rather than necessarily the
+    # associated objects themselves. So with +has_and_belongs_to_many+ and +has_many+
+    # <tt>:through</tt>, the join records will be deleted, but the associated records won't.
+    #
+    # This makes sense if you think about it: if you were to call <tt>post.tags.delete(Tag.find_by_name('food'))</tt>
+    # you would want the 'food' tag to be unlinked from the post, rather than for the tag itself
+    # to be removed from the database.
+    #
+    # However, there are examples where this strategy doesn't make sense. For example, suppose
+    # a person has many projects, and each project has many tasks. If we deleted one of a person's
+    # tasks, we would probably not want the project to be deleted. In this scenario, the delete method
+    # won't actually work: it can only be used if the association on the join model is a
+    # +belongs_to+. In other situations you are expected to perform operations directly on
+    # either the associated records or the <tt>:through</tt> association.
+    #
+    # With a regular +has_many+ there is no distinction between the "associated records"
+    # and the "link", so there is only one choice for what gets deleted.
+    #
+    # With +has_and_belongs_to_many+ and +has_many+ <tt>:through</tt>, if you want to delete the
+    # associated records themselves, you can always do something along the lines of
+    # <tt>person.tasks.each(&:destroy)</tt>.
+    #
     # == Type safety with <tt>ActiveRecord::AssociationTypeMismatch</tt>
     #
     # If you attempt to assign an object to an association that doesn't match the inferred
@@ -828,6 +923,10 @@ module ActiveRecord
       #   Removes one or more objects from the collection by setting their foreign keys to +NULL+.
       #   Objects will be in addition destroyed if they're associated with <tt>:dependent => :destroy</tt>,
       #   and deleted if they're associated with <tt>:dependent => :delete_all</tt>.
+      #
+      #   If the <tt>:through</tt> option is used, then the join records are deleted (rather than
+      #   nullified) by default, but you can specify <tt>:dependent => :destroy</tt> or
+      #   <tt>:dependent => :nullify</tt> to override this.
       # [collection=objects]
       #   Replaces the collections content by deleting and adding objects as appropriate. If the <tt>:through</tt>
       #   option is true callbacks in the join models are triggered except destroy callbacks, since deletion is
@@ -883,7 +982,7 @@ module ActiveRecord
       # * <tt>Firm#clients.create</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save; c</tt>)
       # The declaration can also include an options hash to specialize the behavior of the association.
       #
-      # === Supported options
+      # === Options
       # [:class_name]
       #   Specify the class name of the association. Use it only if that name can't be inferred
       #   from the association name. So <tt>has_many :products</tt> will by default be linked
@@ -911,7 +1010,9 @@ module ActiveRecord
       #   objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. If set to
       #   <tt>:restrict</tt> this object cannot be deleted if it has any associated object.
       #
-      #   *Warning:* This option is ignored when used with <tt>:through</tt> option.
+      #   If using with the <tt>:through</tt> option, the association on the join model must be
+      #   a +belongs_to+, and the records which get deleted are the join records, rather than
+      #   the associated records.
       #
       # [:finder_sql]
       #   Specify a complete SQL statement to fetch the association. This is a good way to go for complex
@@ -991,12 +1092,7 @@ module ActiveRecord
         reflection = create_has_many_reflection(association_id, options, &extension)
         configure_dependency_for_has_many(reflection)
         add_association_callbacks(reflection.name, reflection.options)
-
-        if options[:through]
-          collection_accessor_methods(reflection, HasManyThroughAssociation)
-        else
-          collection_accessor_methods(reflection, HasManyAssociation)
-        end
+        collection_accessor_methods(reflection)
       end
 
       # Specifies a one-to-one association with another class. This method should only be used
@@ -1014,12 +1110,14 @@ module ActiveRecord
       # [build_association(attributes = {})]
       #   Returns a new object of the associated type that has been instantiated
       #   with +attributes+ and linked to this object through a foreign key, but has not
-      #   yet been saved. <b>Note:</b> This ONLY works if an association already exists.
-      #   It will NOT work if the association is +nil+.
+      #   yet been saved.
       # [create_association(attributes = {})]
       #   Returns a new object of the associated type that has been instantiated
       #   with +attributes+, linked to this object through a foreign key, and that
       #   has already been saved (if it passed the validation).
+      # [create_association!(attributes = {})]
+      #   Does the same as <tt>create_association</tt>, but raises <tt>ActiveRecord::RecordInvalid</tt>
+      #   if the record is invalid.
       #
       # (+association+ is replaced with the symbol passed as the first argument, so
       # <tt>has_one :manager</tt> would add among others <tt>manager.nil?</tt>.)
@@ -1031,6 +1129,7 @@ module ActiveRecord
       # * <tt>Account#beneficiary=(beneficiary)</tt> (similar to <tt>beneficiary.account_id = account.id; beneficiary.save</tt>)
       # * <tt>Account#build_beneficiary</tt> (similar to <tt>Beneficiary.new("account_id" => id)</tt>)
       # * <tt>Account#create_beneficiary</tt> (similar to <tt>b = Beneficiary.new("account_id" => id); b.save; b</tt>)
+      # * <tt>Account#create_beneficiary!</tt> (similar to <tt>b = Beneficiary.new("account_id" => id); b.save!; b</tt>)
       #
       # === Options
       #
@@ -1108,14 +1207,12 @@ module ActiveRecord
       def has_one(association_id, options = {})
         if options[:through]
           reflection = create_has_one_through_reflection(association_id, options)
-          association_accessor_methods(reflection, ActiveRecord::Associations::HasOneThroughAssociation)
         else
           reflection = create_has_one_reflection(association_id, options)
-          association_accessor_methods(reflection, HasOneAssociation)
-          association_constructor_method(:build,  reflection, HasOneAssociation)
-          association_constructor_method(:create, reflection, HasOneAssociation)
+          association_constructor_methods(reflection)
           configure_dependency_for_has_one(reflection)
         end
+        association_accessor_methods(reflection)
       end
 
       # Specifies a one-to-one association with another class. This method should only be used
@@ -1137,6 +1234,9 @@ module ActiveRecord
       #   Returns a new object of the associated type that has been instantiated
       #   with +attributes+, linked to this object through a foreign key, and that
       #   has already been saved (if it passed the validation).
+      # [create_association!(attributes = {})]
+      #   Does the same as <tt>create_association</tt>, but raises <tt>ActiveRecord::RecordInvalid</tt>
+      #   if the record is invalid.
       #
       # (+association+ is replaced with the symbol passed as the first argument, so
       # <tt>belongs_to :author</tt> would add among others <tt>author.nil?</tt>.)
@@ -1148,6 +1248,7 @@ module ActiveRecord
       # * <tt>Post#author=(author)</tt> (similar to <tt>post.author_id = author.id</tt>)
       # * <tt>Post#build_author</tt> (similar to <tt>post.author = Author.new</tt>)
       # * <tt>Post#create_author</tt> (similar to <tt>post.author = Author.new; post.author.save; post.author</tt>)
+      # * <tt>Post#create_author!</tt> (similar to <tt>post.author = Author.new; post.author.save!; post.author</tt>)
       # The declaration can also include an options hash to specialize the behavior of the association.
       #
       # === Options
@@ -1169,6 +1270,11 @@ module ActiveRecord
       #   association will use "person_id" as the default <tt>:foreign_key</tt>. Similarly,
       #   <tt>belongs_to :favorite_person, :class_name => "Person"</tt> will use a foreign key
       #   of "favorite_person_id".
+      # [:foreign_type]
+      #   Specify the column used to store the associated object's type, if this is a polymorphic
+      #   association. By default this is guessed to be the name of the association with a "_type"
+      #   suffix. So a class that defines a <tt>belongs_to :taggable, :polymorphic => true</tt>
+      #   association will use "taggable_type" as the default <tt>:foreign_type</tt>.
       # [:primary_key]
       #   Specify the method that returns the primary key of associated object used for the association.
       #   By default this is id.
@@ -1227,16 +1333,12 @@ module ActiveRecord
       def belongs_to(association_id, options = {})
         reflection = create_belongs_to_reflection(association_id, options)
 
-        if reflection.options[:polymorphic]
-          association_accessor_methods(reflection, BelongsToPolymorphicAssociation)
-          association_foreign_type_setter_method(reflection)
-        else
-          association_accessor_methods(reflection, BelongsToAssociation)
-          association_constructor_method(:build,  reflection, BelongsToAssociation)
-          association_constructor_method(:create, reflection, BelongsToAssociation)
+        association_accessor_methods(reflection)
+
+        unless reflection.options[:polymorphic]
+          association_constructor_methods(reflection)
         end
 
-        association_foreign_key_setter_method(reflection)
         add_counter_cache_callbacks(reflection)          if options[:counter_cache]
         add_touch_callbacks(reflection, options[:touch]) if options[:touch]
 
@@ -1271,12 +1373,6 @@ module ActiveRecord
       #     end
       #   end
       #
-      # Deprecated: Any additional fields added to the join table will be placed as attributes when
-      # pulling records out through +has_and_belongs_to_many+ associations. Records returned from join
-      # tables with additional attributes will be marked as readonly (because we can't save changes
-      # to the additional attributes). It's strongly recommended that you upgrade any
-      # associations with attributes to a real join model (see introduction).
-      #
       # Adds the following methods for retrieval and query:
       #
       # [collection(force_reload = false)]
@@ -1419,15 +1515,15 @@ module ActiveRecord
       #   'DELETE FROM developers_projects WHERE active=1 AND developer_id = #{id} AND project_id = #{record.id}'
       def has_and_belongs_to_many(association_id, options = {}, &extension)
         reflection = create_has_and_belongs_to_many_reflection(association_id, options, &extension)
-        collection_accessor_methods(reflection, HasAndBelongsToManyAssociation)
+        collection_accessor_methods(reflection)
 
         # Don't use a before_destroy callback since users' before_destroy
         # callbacks will be executed after the association is wiped out.
         include Module.new {
           class_eval <<-RUBY, __FILE__, __LINE__ + 1
             def destroy                     # def destroy
-              #{reflection.name}.clear      #   posts.clear
               super                         #   super
+              #{reflection.name}.clear      #   posts.clear
             end                             # end
           RUBY
         }
@@ -1451,60 +1547,36 @@ module ActiveRecord
           table_name_prefix + join_table + table_name_suffix
         end
 
-        def association_accessor_methods(reflection, association_proxy_class)
+        def association_accessor_methods(reflection)
           redefine_method(reflection.name) do |*params|
             force_reload = params.first unless params.empty?
-            association = association_instance_get(reflection.name)
-
-            if association.nil? || force_reload
-              association = association_proxy_class.new(self, reflection)
-              retval = force_reload ? reflection.klass.uncached { association.reload } : association.reload
-              if retval.nil? and association_proxy_class == BelongsToAssociation
-                association_instance_set(reflection.name, nil)
-                return nil
-              end
-              association_instance_set(reflection.name, association)
-            end
-
-            association.target.nil? ? nil : association
-          end
-
-          redefine_method("loaded_#{reflection.name}?") do
-            association = association_instance_get(reflection.name)
-            association && association.loaded?
-          end
-
-          redefine_method("#{reflection.name}=") do |new_value|
-            association = association_instance_get(reflection.name)
+            association  = association_proxy(reflection.name)
 
-            if association.nil? || association.target != new_value
-              association = association_proxy_class.new(self, reflection)
+            if force_reload
+              reflection.klass.uncached { association.reload }
+            elsif !association.loaded? || association.stale_target?
+              association.reload
             end
 
-            association.replace(new_value)
-            association_instance_set(reflection.name, new_value.nil? ? nil : association)
+            association.target.nil? ? nil : association
           end
 
-          redefine_method("set_#{reflection.name}_target") do |target|
-            return if target.nil? and association_proxy_class == BelongsToAssociation
-            association = association_proxy_class.new(self, reflection)
-            association.target = target
-            association_instance_set(reflection.name, association)
+          redefine_method("#{reflection.name}=") do |record|
+            association_proxy(reflection.name).replace(record)
           end
         end
 
-        def collection_reader_method(reflection, association_proxy_class)
+        def collection_reader_method(reflection)
           redefine_method(reflection.name) do |*params|
             force_reload = params.first unless params.empty?
-            association = association_instance_get(reflection.name)
+            association  = association_proxy(reflection.name)
 
-            unless association
-              association = association_proxy_class.new(self, reflection)
-              association_instance_set(reflection.name, association)
+            if force_reload
+              reflection.klass.uncached { association.reload }
+            elsif association.stale_target?
+              association.reload
             end
 
-            reflection.klass.uncached { association.reload } if force_reload
-
             association
           end
 
@@ -1512,27 +1584,17 @@ module ActiveRecord
             if send(reflection.name).loaded? || reflection.options[:finder_sql]
               send(reflection.name).map { |r| r.id }
             else
-              if reflection.through_reflection && reflection.source_reflection.belongs_to?
-                through = reflection.through_reflection
-                primary_key = reflection.source_reflection.primary_key_name
-                send(through.name).select("DISTINCT #{through.quoted_table_name}.#{primary_key}").map! { |r| r.send(primary_key) }
-              else
-                send(reflection.name).select("#{reflection.quoted_table_name}.#{reflection.klass.primary_key}").except(:includes).map! { |r| r.id }
-              end
+              send(reflection.name).select("#{reflection.quoted_table_name}.#{reflection.klass.primary_key}").except(:includes).map! { |r| r.id }
             end
           end
-
         end
 
-        def collection_accessor_methods(reflection, association_proxy_class, writer = true)
-          collection_reader_method(reflection, association_proxy_class)
+        def collection_accessor_methods(reflection, writer = true)
+          collection_reader_method(reflection)
 
           if writer
             redefine_method("#{reflection.name}=") do |new_value|
-              # Loads proxy class instance (defined in collection_reader_method) if not already loaded
-              association = send(reflection.name)
-              association.replace(new_value)
-              association
+              association_proxy(reflection.name).replace(new_value)
             end
 
             redefine_method("#{reflection.name.to_s.singularize}_ids=") do |new_value|
@@ -1544,62 +1606,19 @@ module ActiveRecord
           end
         end
 
-        def association_constructor_method(constructor, reflection, association_proxy_class)
-          redefine_method("#{constructor}_#{reflection.name}") do |*params|
-            attributees      = params.first unless params.empty?
-            replace_existing = params[1].nil? ? true : params[1]
-            association      = association_instance_get(reflection.name)
-
-            unless association
-              association = association_proxy_class.new(self, reflection)
-              association_instance_set(reflection.name, association)
-            end
-
-            if association_proxy_class == HasOneAssociation
-              association.send(constructor, attributees, replace_existing)
-            else
-              association.send(constructor, attributees)
-            end
-          end
-        end
-
-        def association_foreign_key_setter_method(reflection)
-          setters = reflect_on_all_associations(:belongs_to).map do |belongs_to_reflection|
-            if belongs_to_reflection.primary_key_name == reflection.primary_key_name
-              "association_instance_set(:#{belongs_to_reflection.name}, nil);"
+        def association_constructor_methods(reflection)
+          constructors = {
+            "build_#{reflection.name}"   => "build",
+            "create_#{reflection.name}"  => "create",
+            "create_#{reflection.name}!" => "create!"
+          }
+
+          constructors.each do |name, proxy_name|
+            redefine_method(name) do |*params|
+              attributes = params.first unless params.empty?
+              association_proxy(reflection.name).send(proxy_name, attributes)
             end
-          end.compact.join
-
-          if method_defined?(:"#{reflection.primary_key_name}=")
-            undef_method :"#{reflection.primary_key_name}="
           end
-
-          class_eval <<-FILE, __FILE__, __LINE__ + 1
-            def #{reflection.primary_key_name}=(new_id)
-              write_attribute :#{reflection.primary_key_name}, new_id
-              if #{reflection.primary_key_name}_changed?
-                #{ setters }
-              end
-            end
-          FILE
-        end
-
-        def association_foreign_type_setter_method(reflection)
-          setters = reflect_on_all_associations(:belongs_to).map do |belongs_to_reflection|
-            if belongs_to_reflection.options[:foreign_type] == reflection.options[:foreign_type]
-              "association_instance_set(:#{belongs_to_reflection.name}, nil);"
-            end
-          end.compact.join
-
-          field = reflection.options[:foreign_type]
-          class_eval <<-FILE, __FILE__, __LINE__ + 1
-            def #{field}=(new_id)
-              write_attribute :#{field}, new_id
-              if #{field}_changed?
-                #{ setters }
-              end
-            end
-          FILE
         end
 
         def add_counter_cache_callbacks(reflection)
@@ -1648,56 +1667,39 @@ module ActiveRecord
         #  - set the foreign key to NULL if the option is set to :nullify
         #  - do not delete the parent record if there is any child record if the
         #    option is set to :restrict
-        #
-        # The +extra_conditions+ parameter, which is not used within the main
-        # Active Record codebase, is meant to allow plugins to define extra
-        # finder conditions.
-        def configure_dependency_for_has_many(reflection, extra_conditions = nil)
-          if reflection.options.include?(:dependent)
+        def configure_dependency_for_has_many(reflection)
+          if reflection.options[:dependent]
+            method_name = "has_many_dependent_for_#{reflection.name}"
+
             case reflection.options[:dependent]
-              when :destroy
-                method_name = "has_many_dependent_destroy_for_#{reflection.name}".to_sym
-                define_method(method_name) do
+            when :destroy, :delete_all, :nullify
+              define_method(method_name) do
+                if reflection.options[:dependent] == :destroy
                   send(reflection.name).each do |o|
                     # No point in executing the counter update since we're going to destroy the parent anyway
                     counter_method = ('belongs_to_counter_cache_before_destroy_for_' + self.class.name.downcase).to_sym
-                    if(o.respond_to? counter_method) then
+                    if o.respond_to?(counter_method)
                       class << o
                         self
                       end.send(:define_method, counter_method, Proc.new {})
                     end
-                    o.destroy
                   end
                 end
-                before_destroy method_name
-              when :delete_all
-                before_destroy do |record|
-                  self.class.send(:delete_all_has_many_dependencies,
-                  record,
-                  reflection.name,
-                  reflection.klass,
-                  reflection.dependent_conditions(record, self.class, extra_conditions))
-                end
-              when :nullify
-                before_destroy do |record|
-                  self.class.send(:nullify_has_many_dependencies,
-                  record,
-                  reflection.name,
-                  reflection.klass,
-                  reflection.primary_key_name,
-                  reflection.dependent_conditions(record, self.class, extra_conditions))
-                end
-              when :restrict
-                method_name = "has_many_dependent_restrict_for_#{reflection.name}".to_sym
-                define_method(method_name) do
-                  unless send(reflection.name).empty?
-                    raise DeleteRestrictionError.new(reflection)
-                  end
+
+                # AssociationProxy#delete_all looks at the :dependent option and acts accordingly
+                send(reflection.name).delete_all
+              end
+            when :restrict
+              define_method(method_name) do
+                unless send(reflection.name).empty?
+                  raise DeleteRestrictionError.new(reflection)
                 end
-                before_destroy method_name
-              else
-                raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, :nullify or :restrict (#{reflection.options[:dependent].inspect})"
+              end
+            else
+              raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, :nullify or :restrict (#{reflection.options[:dependent].inspect})"
             end
+
+            before_destroy method_name
           end
         end
 
@@ -1722,7 +1724,7 @@ module ActiveRecord
                 class_eval <<-eoruby, __FILE__, __LINE__ + 1
                   def #{method_name}
                     association = #{reflection.name}
-                    association.update_attribute(#{reflection.primary_key_name.inspect}, nil) if association
+                    association.update_attribute(#{reflection.foreign_key.inspect}, nil) if association
                   end
                 eoruby
               when :restrict
@@ -1760,14 +1762,6 @@ module ActiveRecord
           end
         end
 
-        def delete_all_has_many_dependencies(record, reflection_name, association_class, dependent_conditions)
-          association_class.delete_all(dependent_conditions)
-        end
-
-        def nullify_has_many_dependencies(record, reflection_name, association_class, primary_key_name, dependent_conditions)
-          association_class.update_all("#{primary_key_name} = NULL", dependent_conditions)
-        end
-
         mattr_accessor :valid_keys_for_has_many_association
         @@valid_keys_for_has_many_association = [
           :class_name, :table_name, :foreign_key, :primary_key,
@@ -1816,13 +1810,7 @@ module ActiveRecord
 
         def create_belongs_to_reflection(association_id, options)
           options.assert_valid_keys(valid_keys_for_belongs_to_association)
-          reflection = create_reflection(:belongs_to, association_id, options, self)
-
-          if options[:polymorphic]
-            reflection.options[:foreign_type] ||= reflection.class_name.underscore + "_type"
-          end
-
-          reflection
+          create_reflection(:belongs_to, association_id, options, self)
         end
 
         mattr_accessor :valid_keys_for_has_and_belongs_to_many_association
@@ -1842,7 +1830,7 @@ module ActiveRecord
 
           reflection = create_reflection(:has_and_belongs_to_many, association_id, options, self)
 
-          if reflection.association_foreign_key == reflection.primary_key_name
+          if reflection.association_foreign_key == reflection.foreign_key
             raise HasAndBelongsToManyAssociationForeignKeyNeeded.new(reflection)
           end
 
diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index 11a7a725e5..ca350f51c9 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -1,4 +1,3 @@
-require 'set'
 require 'active_support/core_ext/array/wrap'
 
 module ActiveRecord
@@ -23,98 +22,55 @@ module ActiveRecord
 
       def select(select = nil)
         if block_given?
-          load_target
-          @target.select.each { |e| yield e }
+          load_target.select.each { |e| yield e }
         else
           scoped.select(select)
         end
       end
 
-      def scoped
-        with_scope(@scope) { @reflection.klass.scoped }
-      end
-
       def find(*args)
-        options = args.extract_options!
-
-        # If using a custom finder_sql, scan the entire collection.
         if @reflection.options[:finder_sql]
-          expects_array = args.first.kind_of?(Array)
-          ids           = args.flatten.compact.uniq.map { |arg| arg.to_i }
-
-          if ids.size == 1
-            id = ids.first
-            record = load_target.detect { |r| id == r.id }
-            expects_array ? [ record ] : record
-          else
-            load_target.select { |r| ids.include?(r.id) }
-          end
+          find_by_scan(*args)
         else
-          merge_options_from_reflection!(options)
-          construct_find_options!(options)
-
-          with_scope(:find => @scope[:find].slice(:conditions, :order)) do
-            relation = @reflection.klass.send(:construct_finder_arel, options, @reflection.klass.send(:current_scoped_methods))
-
-            case args.first
-            when :first, :last
-              relation.send(args.first)
-            when :all
-              records = relation.all
-              @reflection.options[:uniq] ? uniq(records) : records
-            else
-              relation.find(*args)
-            end
-          end
+          scoped.find(*args)
         end
       end
 
-      # Fetches the first one using SQL if possible.
       def first(*args)
-        if fetch_first_or_last_using_find?(args)
-          find(:first, *args)
-        else
-          load_target unless loaded?
-          args = args[1..-1] if args.first.kind_of?(Hash) && args.first.empty?
-          @target.first(*args)
-        end
+        first_or_last(:first, *args)
       end
 
-      # Fetches the last one using SQL if possible.
       def last(*args)
-        if fetch_first_or_last_using_find?(args)
-          find(:last, *args)
-        else
-          load_target unless loaded?
-          @target.last(*args)
-        end
+        first_or_last(:last, *args)
       end
 
       def to_ary
-        load_target
-        if @target.is_a?(Array)
-          @target.to_ary
-        else
-          Array.wrap(@target)
-        end
+        load_target.dup
       end
       alias_method :to_a, :to_ary
 
       def reset
-        reset_target!
-        reset_scopes_cache!
-        @loaded = false
+        @_scopes_cache = {}
+        @loaded        = false
+        @target        = []
       end
 
       def build(attributes = {}, &block)
-        if attributes.is_a?(Array)
-          attributes.collect { |attr| build(attr, &block) }
-        else
-          build_record(attributes) do |record|
-            block.call(record) if block_given?
-            set_belongs_to_association_for(record)
-          end
+        build_or_create(attributes, :build, &block)
+      end
+
+      def create(attributes = {}, &block)
+        unless @owner.persisted?
+          raise ActiveRecord::RecordNotSaved, "You cannot call create unless the parent is saved"
         end
+
+        build_or_create(attributes, :create, &block)
+      end
+
+      def create!(attrs = {}, &block)
+        record = create(attrs, &block)
+        Array.wrap(record).each(&:save!)
+        record
       end
 
       # Add +records+ to this association.  Returns +self+ so method calls may be chained.
@@ -124,9 +80,9 @@ module ActiveRecord
         load_target if @owner.new_record?
 
         transaction do
-          flatten_deeper(records).each do |record|
+          records.flatten.each do |record|
             raise_on_type_mismatch(record)
-            add_record_to_target_with_callbacks(record) do |r|
+            add_to_target(record) do |r|
               result &&= insert_record(record) unless @owner.new_record?
             end
           end
@@ -157,18 +113,35 @@ module ActiveRecord
       #
       # See delete for more info.
       def delete_all
-        load_target
-        delete(@target)
-        reset_target!
-        reset_scopes_cache!
+        delete(load_target).tap do
+          reset
+          loaded!
+        end
+      end
+
+      # Identical to delete_all, except that the return value is the association (for chaining)
+      # rather than the records which have been removed.
+      def clear
+        delete_all
+        self
+      end
+
+      # Destroy all the records from this association.
+      #
+      # See destroy for more info.
+      def destroy_all
+        destroy(load_target).tap do
+          reset
+          loaded!
+        end
       end
 
       # Calculate sum using SQL, not Enumerable
       def sum(*args)
         if block_given?
-          calculate(:sum, *args) { |*block_args| yield(*block_args) }
+          scoped.sum(*args) { |*block_args| yield(*block_args) }
         else
-          calculate(:sum, *args)
+          scoped.sum(*args)
         end
       end
 
@@ -185,14 +158,13 @@ module ActiveRecord
 
           @reflection.klass.count_by_sql(custom_counter_sql)
         else
-
           if @reflection.options[:uniq]
             # This is needed because 'SELECT count(DISTINCT *)..' is not valid SQL.
-            column_name = "#{@reflection.quoted_table_name}.#{@reflection.klass.primary_key}" unless column_name
+            column_name ||= @reflection.klass.primary_key
             options.merge!(:distinct => true)
           end
 
-          value = @reflection.klass.send(:with_scope, @scope) { @reflection.klass.count(column_name, options) }
+          value = scoped.count(column_name, options)
 
           limit  = @reflection.options[:limit]
           offset = @reflection.options[:offset]
@@ -213,10 +185,7 @@ module ActiveRecord
       # are actually removed from the database, that depends precisely on
       # +delete_records+. They are in any case removed from the collection.
       def delete(*records)
-        remove_records(records) do |_records, old_records|
-          delete_records(old_records) if old_records.any?
-          _records.each { |record| @target.delete(record) }
-        end
+        delete_or_destroy(records, @reflection.options[:dependent])
       end
 
       # Destroy +records+ and remove them from this association calling
@@ -225,54 +194,8 @@ module ActiveRecord
       # Note that this method will _always_ remove records from the database
       # ignoring the +:dependent+ option.
       def destroy(*records)
-        records = find(records) if records.any? {|record| record.kind_of?(Fixnum) || record.kind_of?(String)}
-        remove_records(records) do |_records, old_records|
-          old_records.each { |record| record.destroy }
-        end
-
-        load_target
-      end
-
-      # Removes all records from this association.  Returns +self+ so method calls may be chained.
-      def clear
-        unless length.zero? # forces load_target if it hasn't happened already
-          if @reflection.options[:dependent] == :destroy
-            destroy_all
-          else
-            delete_all
-          end
-        end
-
-        self
-      end
-
-      # Destroy all the records from this association.
-      #
-      # See destroy for more info.
-      def destroy_all
-        load_target
-        destroy(@target).tap do
-          reset_target!
-          reset_scopes_cache!
-        end
-      end
-
-      def create(attrs = {})
-        if attrs.is_a?(Array)
-          attrs.collect { |attr| create(attr) }
-        else
-          create_record(attrs) do |record|
-            yield(record) if block_given?
-            record.save
-          end
-        end
-      end
-
-      def create!(attrs = {})
-        create_record(attrs) do |record|
-          yield(record) if block_given?
-          record.save!
-        end
+        records = find(records) if records.any? { |record| record.kind_of?(Fixnum) || record.kind_of?(String) }
+        delete_or_destroy(records, :destroy)
       end
 
       # Returns the size of the collection by executing a SELECT COUNT(*)
@@ -316,7 +239,7 @@ module ActiveRecord
 
       def any?
         if block_given?
-          method_missing(:any?) { |*block_args| yield(*block_args) }
+          load_target.any? { |*block_args| yield(*block_args) }
         else
           !empty?
         end
@@ -325,7 +248,7 @@ module ActiveRecord
       # Returns true if the collection has more than 1 record. Equivalent to collection.size > 1.
       def many?
         if block_given?
-          method_missing(:many?) { |*block_args| yield(*block_args) }
+          load_target.many? { |*block_args| yield(*block_args) }
         else
           size > 1
         end
@@ -342,108 +265,117 @@ module ActiveRecord
       # This will perform a diff and delete/add only records that have changed.
       def replace(other_array)
         other_array.each { |val| raise_on_type_mismatch(val) }
-
-        load_target
-        other   = other_array.size < 100 ? other_array : other_array.to_set
-        current = @target.size < 100 ? @target : @target.to_set
+        original_target = load_target.dup
 
         transaction do
-          delete(@target.select { |v| !other.include?(v) })
-          concat(other_array.select { |v| !current.include?(v) })
+          delete(@target - other_array)
+
+          unless concat(other_array - @target)
+            @target = original_target
+            raise RecordNotSaved, "Failed to replace #{@reflection.name} because one or more of the " \
+                                  "new records could not be saved."
+          end
         end
       end
 
       def include?(record)
-        return false unless record.is_a?(@reflection.klass)
-        return include_in_memory?(record) if record.new_record?
-        load_target if @reflection.options[:finder_sql] && !loaded?
-        loaded? ? @target.include?(record) : exists?(record)
+        if record.is_a?(@reflection.klass)
+          if record.new_record?
+            include_in_memory?(record)
+          else
+            load_target if @reflection.options[:finder_sql]
+            loaded? ? @target.include?(record) : scoped.exists?(record)
+          end
+        else
+          false
+        end
       end
 
-      def proxy_respond_to?(method, include_private = false)
+      def respond_to?(method, include_private = false)
         super || @reflection.klass.respond_to?(method, include_private)
       end
 
+      def method_missing(method, *args, &block)
+        match = DynamicFinderMatch.match(method)
+        if match && match.creator?
+          attributes = match.attribute_names
+          return send(:"find_by_#{attributes.join('_and_')}", *args) || create(Hash[attributes.zip(args)])
+        end
+
+        if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
+          super
+        elsif @reflection.klass.scopes[method]
+          @_scopes_cache ||= {}
+          @_scopes_cache[method] ||= {}
+          @_scopes_cache[method][args] ||= scoped.readonly(nil).send(method, *args)
+        else
+          scoped.readonly(nil).send(method, *args, &block)
+        end
+      end
+
       protected
-        def construct_find_options!(options)
+
+        def association_scope
+          options = @reflection.options.slice(:order, :limit, :joins, :group, :having, :offset)
+          super.apply_finder_options(options)
         end
 
         def load_target
-          if !@owner.new_record? || foreign_key_present
+          if find_target?
+            targets = []
+
             begin
-              unless loaded?
-                if @target.is_a?(Array) && @target.any?
-                  @target = find_target.map do |f|
-                    i = @target.index(f)
-                    if i
-                      @target.delete_at(i).tap do |t|
-                        keys = ["id"] + t.changes.keys + (f.attribute_names - t.attribute_names)
-                        f.attributes.except(*keys).each do |k,v|
-                          t.send("#{k}=", v)
-                        end
-                      end
-                    else
-                      f
-                    end
-                  end + @target
-                else
-                  @target = find_target
-                end
-              end
+              targets = find_target
             rescue ActiveRecord::RecordNotFound
               reset
             end
+
+            @target = merge_target_lists(targets, @target)
           end
 
-          loaded if target
+          loaded!
           target
         end
 
-        def method_missing(method, *args)
-          match = DynamicFinderMatch.match(method)
-          if match && match.creator?
-            attributes = match.attribute_names
-            return send(:"find_by_#{attributes.join('_and_')}", *args) || create(Hash[attributes.zip(args)])
-          end
+        def add_to_target(record)
+          transaction do
+            callback(:before_add, record)
+            yield(record) if block_given?
 
-          if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
-            super
-          elsif @reflection.klass.scopes[method]
-            @_scopes_cache ||= {}
-            @_scopes_cache[method] ||= {}
-            @_scopes_cache[method][args] ||= with_scope(@scope) { @reflection.klass.send(method, *args) }
-          else
-            with_scope(@scope) do
-              if block_given?
-                @reflection.klass.send(method, *args) { |*block_args| yield(*block_args) }
-              else
-                @reflection.klass.send(method, *args)
-              end
+            if @reflection.options[:uniq] && index = @target.index(record)
+              @target[index] = record
+            else
+              @target << record
             end
+
+            callback(:after_add, record)
+            set_inverse_instance(record)
           end
+
+          record
+        end
+
+      private
+
+        def select_value
+          super || uniq_select_value
+        end
+
+        def uniq_select_value
+          @reflection.options[:uniq] && "DISTINCT #{@reflection.quoted_table_name}.*"
         end
 
         def custom_counter_sql
           if @reflection.options[:counter_sql]
-            counter_sql = @reflection.options[:counter_sql]
+            interpolate(@reflection.options[:counter_sql])
           else
             # replace the SELECT clause with COUNT(*), preserving any hints within /* ... */
-            counter_sql = @reflection.options[:finder_sql].sub(/SELECT\b(\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }
+            interpolate(@reflection.options[:finder_sql]).sub(/SELECT\b(\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }
           end
-
-          interpolate_sql(counter_sql)
         end
 
         def custom_finder_sql
-          interpolate_sql(@reflection.options[:finder_sql])
-        end
-
-        def reset_target!
-          @target = Array.new
-        end
-
-        def reset_scopes_cache!
-          @_scopes_cache = {}
+          interpolate(@reflection.options[:finder_sql])
         end
 
         def find_target
@@ -455,65 +387,74 @@ module ActiveRecord
             end
 
           records = @reflection.options[:uniq] ? uniq(records) : records
-          records.each do |record|
-            set_inverse_instance(record, @owner)
-          end
+          records.each { |record| set_inverse_instance(record) }
           records
         end
 
-        def add_record_to_target_with_callbacks(record)
-          callback(:before_add, record)
-          yield(record) if block_given?
-          @target ||= [] unless loaded?
-          if index = @target.index(record)
-            @target[index] = record
-          else
-             @target << record
-          end
-          callback(:after_add, record)
-          set_inverse_instance(record, @owner)
-          record
+        def merge_target_lists(loaded, existing)
+          return loaded if existing.empty?
+          return existing if loaded.empty?
+
+          loaded.map do |f|
+            i = existing.index(f)
+            if i
+              existing.delete_at(i).tap do |t|
+                keys = ["id"] + t.changes.keys + (f.attribute_names - t.attribute_names)
+                # FIXME: this call to attributes causes many NoMethodErrors
+                attributes = f.attributes
+                (attributes.keys - keys).each do |k|
+                  t.send("#{k}=", attributes[k])
+                end
+              end
+            else
+              f
+            end
+          end + existing
         end
 
-      private
-        def create_record(attrs)
-          attrs.update(@reflection.options[:conditions]) if @reflection.options[:conditions].is_a?(Hash)
-          ensure_owner_is_persisted!
-
-          scoped_where = scoped.where_values_hash
-          create_scope = scoped_where ? @scope[:create].merge(scoped_where) : @scope[:create]
-          record = @reflection.klass.send(:with_scope, :create => create_scope) do
-            @reflection.build_association(attrs)
-          end
-          if block_given?
-            add_record_to_target_with_callbacks(record) { |*block_args| yield(*block_args) }
-          else
-            add_record_to_target_with_callbacks(record)
+        def build_or_create(attributes, method)
+          records = Array.wrap(attributes).map do |attrs|
+            record = build_record(attrs)
+
+            add_to_target(record) do
+              yield(record) if block_given?
+              insert_record(record) if method == :create
+            end
           end
+
+          attributes.is_a?(Array) ? records : records.first
         end
 
-        def build_record(attrs)
-          attrs.update(@reflection.options[:conditions]) if @reflection.options[:conditions].is_a?(Hash)
-          record = @reflection.build_association(attrs)
-          if block_given?
-            add_record_to_target_with_callbacks(record) { |*block_args| yield(*block_args) }
-          else
-            add_record_to_target_with_callbacks(record)
-          end
+        # Do the relevant stuff to insert the given record into the association collection.
+        def insert_record(record, validate = true)
+          raise NotImplementedError
         end
 
-        def remove_records(*records)
-          records = flatten_deeper(records)
+        def build_record(attributes)
+          @reflection.build_association(scoped.scope_for_create.merge(attributes))
+        end
+
+        def delete_or_destroy(records, method)
+          records = records.flatten
           records.each { |record| raise_on_type_mismatch(record) }
+          existing_records = records.reject { |r| r.new_record? }
 
           transaction do
             records.each { |record| callback(:before_remove, record) }
-            old_records = records.reject { |r| r.new_record? }
-            yield(records, old_records)
+
+            delete_records(existing_records, method) if existing_records.any?
+            records.each { |record| @target.delete(record) }
+
             records.each { |record| callback(:after_remove, record) }
           end
         end
 
+        # Delete the given records from the association, using one of the methods :destroy,
+        # :delete_all or :nullify (or nil, in which case a default is used).
+        def delete_records(records, method)
+          raise NotImplementedError
+        end
+
         def callback(method, record)
           callbacks_for(method).each do |callback|
             case callback
@@ -532,27 +473,61 @@ module ActiveRecord
           @owner.class.send(full_callback_name.to_sym) || []
         end
 
-        def ensure_owner_is_persisted!
-          unless @owner.persisted?
-            raise ActiveRecord::RecordNotSaved, "You cannot call create unless the parent is saved"
-          end
-        end
-
+        # Should we deal with assoc.first or assoc.last by issuing an independent query to
+        # the database, or by getting the target, and then taking the first/last item from that?
+        #
+        # If the args is just a non-empty options hash, go to the database.
+        #
+        # Otherwise, go to the database only if none of the following are true:
+        #   * target already loaded
+        #   * owner is new record
+        #   * custom :finder_sql exists
+        #   * target contains new or changed record(s)
+        #   * the first arg is an integer (which indicates the number of records to be returned)
         def fetch_first_or_last_using_find?(args)
-          (args.first.kind_of?(Hash) && !args.first.empty?) || !(loaded? || @owner.new_record? || @reflection.options[:finder_sql] ||
-            @target.any? { |record| record.new_record? } || args.first.kind_of?(Integer))
+          if args.first.is_a?(Hash)
+            true
+          else
+            !(loaded? ||
+              @owner.new_record? ||
+              @reflection.options[:finder_sql] ||
+              @target.any? { |record| record.new_record? || record.changed? } ||
+              args.first.kind_of?(Integer))
+          end
         end
 
         def include_in_memory?(record)
           if @reflection.is_a?(ActiveRecord::Reflection::ThroughReflection)
-            @owner.send(proxy_reflection.through_reflection.name.to_sym).any? do |source|
+            @owner.send(proxy_reflection.through_reflection.name).any? { |source|
               target = source.send(proxy_reflection.source_reflection.name)
               target.respond_to?(:include?) ? target.include?(record) : target == record
-            end
+            } || @target.include?(record)
           else
             @target.include?(record)
           end
         end
+
+        # If using a custom finder_sql, #find scans the entire collection.
+        def find_by_scan(*args)
+          expects_array = args.first.kind_of?(Array)
+          ids           = args.flatten.compact.uniq.map { |arg| arg.to_i }
+
+          if ids.size == 1
+            id = ids.first
+            record = load_target.detect { |r| id == r.id }
+            expects_array ? [ record ] : record
+          else
+            load_target.select { |r| ids.include?(r.id) }
+          end
+        end
+
+        # Fetches the first/last using SQL if possible, otherwise from the target array.
+        def first_or_last(type, *args)
+          args.shift if args.first.is_a?(Hash) && args.first.empty?
+
+          collection = fetch_first_or_last_using_find?(args) ? scoped : load_target
+          collection.send(type, *args)
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations/association_proxy.rb b/activerecord/lib/active_record/associations/association_proxy.rb
index 53ec5a0da6..d16cda5585 100644
--- a/activerecord/lib/active_record/associations/association_proxy.rb
+++ b/activerecord/lib/active_record/associations/association_proxy.rb
@@ -4,17 +4,18 @@ module ActiveRecord
   module Associations
     # = Active Record Associations
     #
-    # This is the root class of all association proxies:
+    # This is the root class of all association proxies ('+ Foo' signifies an included module Foo):
     #
     #   AssociationProxy
-    #     BelongsToAssociation
+    #     SingularAssociaton
     #       HasOneAssociation
-    #     BelongsToPolymorphicAssociation
+    #         HasOneThroughAssociation + ThroughAssociation
+    #       BelongsToAssociation
+    #         BelongsToPolymorphicAssociation
     #     AssociationCollection
     #       HasAndBelongsToManyAssociation
     #       HasManyAssociation
-    #         HasManyThroughAssociation
-    #            HasOneThroughAssociation
+    #         HasManyThroughAssociation + ThroughAssociation
     #
     # Association proxies in Active Record are middlemen between the object that
     # holds the association, known as the <tt>@owner</tt>, and the actual associated
@@ -50,10 +51,9 @@ module ActiveRecord
     # is computed directly through SQL and does not trigger by itself the
     # instantiation of the actual post records.
     class AssociationProxy #:nodoc:
-      alias_method :proxy_respond_to?, :respond_to?
       alias_method :proxy_extend, :extend
-      delegate :to_param, :to => :proxy_target
-      instance_methods.each { |m| undef_method m unless m.to_s =~ /^(?:nil\?|send|object_id|to_a)$|^__|^respond_to_missing|proxy_/ }
+
+      instance_methods.each { |m| undef_method m unless m.to_s =~ /^(?:nil\?|send|object_id|to_a)$|^__|^respond_to|proxy_/ }
 
       def initialize(owner, reflection)
         @owner, @reflection = owner, reflection
@@ -64,6 +64,10 @@ module ActiveRecord
         construct_scope
       end
 
+      def to_param
+        proxy_target.to_param
+      end
+
       # Returns the owner of the proxy.
       def proxy_owner
         @owner
@@ -75,21 +79,25 @@ module ActiveRecord
         @reflection
       end
 
-      # Returns the \target of the proxy, same as +target+.
-      def proxy_target
-        @target
-      end
-
       # Does the proxy or its \target respond to +symbol+?
       def respond_to?(*args)
-        proxy_respond_to?(*args) || (load_target && @target.respond_to?(*args))
+        super || (load_target && @target.respond_to?(*args))
+      end
+
+      # Forwards any missing method call to the \target.
+      def method_missing(method, *args, &block)
+        if load_target
+          return super unless @target.respond_to?(method)
+          @target.send(method, *args, &block)
+        end
+      rescue NoMethodError => e
+        raise e, e.message.sub(/ for #<.*$/, " via proxy for #{@target}")
       end
 
       # Forwards <tt>===</tt> explicitly to the \target because the instance method
       # removal above doesn't catch it. Loads the \target if needed.
       def ===(other)
-        load_target
-        other === @target
+        other === load_target
       end
 
       # Returns the name of the table of the related class:
@@ -100,13 +108,6 @@ module ActiveRecord
         @reflection.klass.table_name
       end
 
-      # Returns the SQL string that corresponds to the <tt>:conditions</tt>
-      # option of the macro, if given, or +nil+ otherwise.
-      def conditions
-        @conditions ||= interpolate_sql(@reflection.sanitized_conditions) if @reflection.sanitized_conditions
-      end
-      alias :sql_conditions :conditions
-
       # Resets the \loaded flag to +false+ and sets the \target to +nil+.
       def reset
         @loaded = false
@@ -117,6 +118,7 @@ module ActiveRecord
       # Reloads the \target and returns +self+ on success.
       def reload
         reset
+        construct_scope
         load_target
         self unless @target.nil?
       end
@@ -127,117 +129,93 @@ module ActiveRecord
       end
 
       # Asserts the \target has been loaded setting the \loaded flag to +true+.
-      def loaded
-        @loaded = true
+      def loaded!
+        @loaded      = true
+        @stale_state = stale_state
       end
 
-      # Returns the target of this proxy, same as +proxy_target+.
-      def target
-        @target
+      # The target is stale if the target no longer points to the record(s) that the
+      # relevant foreign_key(s) refers to. If stale, the association accessor method
+      # on the owner will reload the target. It's up to subclasses to implement the
+      # state_state method if relevant.
+      #
+      # Note that if the target has not been loaded, it is not considered stale.
+      def stale_target?
+        loaded? && @stale_state != stale_state
       end
 
+      # Returns the target of this proxy, same as +proxy_target+.
+      attr_reader :target
+
+      # Returns the \target of the proxy, same as +target+.
+      alias :proxy_target :target
+
       # Sets the target of this proxy to <tt>\target</tt>, and the \loaded flag to +true+.
       def target=(target)
         @target = target
-        loaded
+        loaded!
       end
 
       # Forwards the call to the target. Loads the \target if needed.
       def inspect
-        load_target
-        @target.inspect
+        load_target.inspect
       end
 
       def send(method, *args)
-        if proxy_respond_to?(method)
-          super
-        else
-          load_target
-          @target.send(method, *args)
-        end
+        return super if respond_to?(method)
+        load_target.send(method, *args)
       end
 
-      protected
-        # Does the association have a <tt>:dependent</tt> option?
-        def dependent?
-          @reflection.options[:dependent]
-        end
+      def scoped
+        target_scope.merge(@association_scope)
+      end
 
-        def interpolate_sql(sql, record = nil)
-          @owner.send(:interpolate_sql, sql, record)
-        end
+      protected
 
-        # Forwards the call to the reflection class.
-        def sanitize_sql(sql, table_name = @reflection.klass.table_name)
-          @reflection.klass.send(:sanitize_sql, sql, table_name)
+        # Construct the scope for this association.
+        #
+        # Note that the association_scope is merged into the targed_scope only when the
+        # scoped method is called. This is because at that point the call may be surrounded
+        # by scope.scoping { ... } or with_scope { ... } etc, which affects the scope which
+        # actually gets built.
+        def construct_scope
+          @association_scope = association_scope if target_klass
         end
 
-        # Assigns the ID of the owner to the corresponding foreign key in +record+.
-        # If the association is polymorphic the type of the owner is also set.
-        def set_belongs_to_association_for(record)
-          if @reflection.options[:as]
-            record["#{@reflection.options[:as]}_id"]   = @owner.id if @owner.persisted?
-            record["#{@reflection.options[:as]}_type"] = @owner.class.base_class.name.to_s
-          else
-            if @owner.persisted?
-              primary_key = @reflection.options[:primary_key] || :id
-              record[@reflection.primary_key_name] = @owner.send(primary_key)
-            end
+        def association_scope
+          scope = target_klass.unscoped
+          scope = scope.create_with(creation_attributes)
+          scope = scope.apply_finder_options(@reflection.options.slice(:readonly, :include))
+          scope = scope.where(interpolate(@reflection.options[:conditions]))
+          if select = select_value
+            scope = scope.select(select)
           end
+          scope = scope.extending(*Array.wrap(@reflection.options[:extend]))
+          scope.where(construct_owner_conditions)
         end
 
-        # Merges into +options+ the ones coming from the reflection.
-        def merge_options_from_reflection!(options)
-          options.reverse_merge!(
-            :group   => @reflection.options[:group],
-            :having  => @reflection.options[:having],
-            :limit   => @reflection.options[:limit],
-            :offset  => @reflection.options[:offset],
-            :joins   => @reflection.options[:joins],
-            :include => @reflection.options[:include],
-            :select  => @reflection.options[:select],
-            :readonly  => @reflection.options[:readonly]
-          )
+        def aliased_table
+          target_klass.arel_table
         end
 
-        # Forwards +with_scope+ to the reflection.
-        def with_scope(*args, &block)
-          @reflection.klass.send :with_scope, *args, &block
-        end
-
-        # Construct the scope used for find/create queries on the target
-        def construct_scope
-          @scope = {
-            :find   => construct_find_scope,
-            :create => construct_create_scope
-          }
+        # Set the inverse association, if possible
+        def set_inverse_instance(record)
+          if record && invertible_for?(record)
+            inverse = record.send(:association_proxy, inverse_reflection_for(record).name)
+            inverse.target = @owner
+          end
         end
 
-        # Implemented by subclasses
-        def construct_find_scope
-          raise NotImplementedError
+        # This class of the target. belongs_to polymorphic overrides this to look at the
+        # polymorphic_type field on the owner.
+        def target_klass
+          @reflection.klass
         end
 
-        # Implemented by (some) subclasses
-        def construct_create_scope
-          {}
-        end
-
-      private
-        # Forwards any missing method call to the \target.
-        def method_missing(method, *args)
-          if load_target
-            unless @target.respond_to?(method)
-              message = "undefined method `#{method.to_s}' for \"#{@target}\":#{@target.class.to_s}"
-              raise NoMethodError, message
-            end
-
-            if block_given?
-              @target.send(method, *args)  { |*block_args| yield(*block_args) }
-            else
-              @target.send(method, *args)
-            end
-          end
+        # Can be overridden (i.e. in ThroughAssociation) to merge in other scopes (i.e. the
+        # through association's scope)
+        def target_scope
+          target_klass.scoped
         end
 
         # Loads the \target if needed and returns it.
@@ -251,26 +229,84 @@ module ActiveRecord
         # ActiveRecord::RecordNotFound is rescued within the method, and it is
         # not reraised. The proxy is \reset and +nil+ is the return value.
         def load_target
-          return nil unless defined?(@loaded)
-
-          if !loaded? && (!@owner.new_record? || foreign_key_present)
-            if IdentityMap.enabled? && association_class
-              @target = IdentityMap.get(association_class, @owner[@reflection.association_foreign_key])
+          if find_target?
+            begin
+            if IdentityMap.enabled? && association_class && association_class.respond_to?(:base_class)
+              @target = IdentityMap.get(association_class, @owner[@reflection.foreign_key])
+            end
+            rescue NameError
+              nil
+            ensure
+              @target ||= find_target
             end
-            @target ||= find_target
           end
-
-          @loaded = true
-          @target
+          loaded!
+          target
         rescue ActiveRecord::RecordNotFound
           reset
         end
 
-        # Can be overwritten by associations that might have the foreign key
-        # available for an association without having the object itself (and
-        # still being a new record). Currently, only +belongs_to+ presents
-        # this scenario (both vanilla and polymorphic).
-        def foreign_key_present
+      private
+
+        def find_target?
+          !loaded? && (!@owner.new_record? || foreign_key_present?) && target_klass
+        end
+
+        def interpolate(sql, record = nil)
+          if sql.respond_to?(:to_proc)
+            @owner.send(:instance_exec, record, &sql)
+          else
+            sql
+          end
+        end
+
+        def select_value
+          @reflection.options[:select]
+        end
+
+        # Implemented by (some) subclasses
+        def creation_attributes
+          { }
+        end
+
+        # Returns a hash linking the owner to the association represented by the reflection
+        def construct_owner_attributes(reflection = @reflection)
+          attributes = {}
+          if reflection.macro == :belongs_to
+            attributes[reflection.association_primary_key] = @owner[reflection.foreign_key]
+          else
+            attributes[reflection.foreign_key] = @owner[reflection.active_record_primary_key]
+
+            if reflection.options[:as]
+              attributes["#{reflection.options[:as]}_type"] = @owner.class.base_class.name
+            end
+          end
+          attributes
+        end
+
+        # Builds an array of arel nodes from the owner attributes hash
+        def construct_owner_conditions(table = aliased_table, reflection = @reflection)
+          conditions = construct_owner_attributes(reflection).map do |attr, value|
+            table[attr].eq(value)
+          end
+          table.create_and(conditions)
+        end
+
+        # Sets the owner attributes on the given record
+        def set_owner_attributes(record)
+          if @owner.persisted?
+            construct_owner_attributes.each { |key, value| record[key] = value }
+          end
+        end
+
+        # Should be true if there is a foreign key present on the @owner which
+        # references the target. This is used to determine whether we can load
+        # the target if the @owner is currently a new record (and therefore
+        # without a key).
+        #
+        # Currently implemented by belongs_to (vanilla and polymorphic) and
+        # has_one/has_many :through associations which go through a belongs_to
+        def foreign_key_present?
           false
         end
 
@@ -284,34 +320,24 @@ module ActiveRecord
           end
         end
 
-        if RUBY_VERSION < '1.9.2'
-          # Array#flatten has problems with recursive arrays before Ruby 1.9.2.
-          # Going one level deeper solves the majority of the problems.
-          def flatten_deeper(array)
-            array.collect { |element| (element.respond_to?(:flatten) && !element.is_a?(Hash)) ? element.flatten : element }.flatten
-          end
-        else
-          def flatten_deeper(array)
-            array.flatten
-          end
+        # Can be redefined by subclasses, notably polymorphic belongs_to
+        # The record parameter is necessary to support polymorphic inverses as we must check for
+        # the association in the specific class of the record.
+        def inverse_reflection_for(record)
+          @reflection.inverse_of
         end
 
-        # Returns the ID of the owner, quoted if needed.
-        def owner_quoted_id
-          @owner.quoted_id
+        # Is this association invertible? Can be redefined by subclasses.
+        def invertible_for?(record)
+          inverse_reflection_for(record)
         end
 
-        def set_inverse_instance(record, instance)
-          return if record.nil? || !we_can_set_the_inverse_on_this?(record)
-          inverse_relationship = @reflection.inverse_of
-          unless inverse_relationship.nil?
-            record.send(:"set_#{inverse_relationship.name}_target", instance)
-          end
-        end
-
-        # Override in subclasses
-        def we_can_set_the_inverse_on_this?(record)
-          false
+        # This should be implemented to return the values of the relevant key(s) on the owner,
+        # so that when state_state is different from the value stored on the last find_target,
+        # the target is stale.
+        #
+        # This is only relevant to certain associations, which is why it returns nil by default.
+        def stale_state
         end
 
         def association_class
diff --git a/activerecord/lib/active_record/associations/belongs_to_association.rb b/activerecord/lib/active_record/associations/belongs_to_association.rb
index b438620c8f..178c7204f8 100644
--- a/activerecord/lib/active_record/associations/belongs_to_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_association.rb
@@ -1,41 +1,17 @@
 module ActiveRecord
   # = Active Record Belongs To Associations
   module Associations
-    class BelongsToAssociation < AssociationProxy #:nodoc:
-      def create(attributes = {})
-        replace(@reflection.create_association(attributes))
-      end
-
-      def build(attributes = {})
-        replace(@reflection.build_association(attributes))
-      end
-
+    class BelongsToAssociation < SingularAssociation #:nodoc:
       def replace(record)
-        counter_cache_name = @reflection.counter_cache_column
-
-        if record.nil?
-          if counter_cache_name && @owner.persisted?
-            @reflection.klass.decrement_counter(counter_cache_name, previous_record_id) if @owner[@reflection.primary_key_name]
-          end
-
-          @target = @owner[@reflection.primary_key_name] = nil
-        else
-          raise_on_type_mismatch(record)
+        record = check_record(record)
 
-          if counter_cache_name && @owner.persisted? && record.id != @owner[@reflection.primary_key_name]
-            @reflection.klass.increment_counter(counter_cache_name, record.id)
-            @reflection.klass.decrement_counter(counter_cache_name, @owner[@reflection.primary_key_name]) if @owner[@reflection.primary_key_name]
-          end
-
-          @target = (AssociationProxy === record ? record.target : record)
-          @owner[@reflection.primary_key_name] = record_id(record) if record.persisted?
-          @updated = true
-        end
+        update_counters(record)
+        replace_keys(record)
+        set_inverse_instance(record)
 
-        set_inverse_instance(record, @owner)
+        @updated = true if record
 
-        loaded
-        record
+        self.target = record
       end
 
       def updated?
@@ -43,50 +19,52 @@ module ActiveRecord
       end
 
       private
-        def find_target
-          find_method = if @reflection.options[:primary_key]
-                          "find_by_#{@reflection.options[:primary_key]}"
-                        else
-                          "find"
-                        end
 
-          options = @reflection.options.dup.slice(:select, :include, :readonly)
+        def update_counters(record)
+          counter_cache_name = @reflection.counter_cache_column
+
+          if counter_cache_name && @owner.persisted? && different_target?(record)
+            if record
+              record.class.increment_counter(counter_cache_name, record.id)
+            end
 
-          the_target = with_scope(:find => @scope[:find]) do
-            @reflection.klass.send(find_method,
-              @owner[@reflection.primary_key_name],
-              options
-            ) if @owner[@reflection.primary_key_name]
+            if foreign_key_present?
+              target_klass.decrement_counter(counter_cache_name, target_id)
+            end
           end
-          set_inverse_instance(the_target, @owner)
-          the_target
         end
 
-        def construct_find_scope
-          { :conditions => conditions }
+        # Checks whether record is different to the current target, without loading it
+        def different_target?(record)
+          record.nil? && @owner[@reflection.foreign_key] ||
+          record.id   != @owner[@reflection.foreign_key]
         end
 
-        def foreign_key_present
-          !@owner[@reflection.primary_key_name].nil?
+        def replace_keys(record)
+          @owner[@reflection.foreign_key] = record && record[@reflection.association_primary_key]
+        end
+
+        def foreign_key_present?
+          @owner[@reflection.foreign_key]
         end
 
         # NOTE - for now, we're only supporting inverse setting from belongs_to back onto
         # has_one associations.
-        def we_can_set_the_inverse_on_this?(record)
-          @reflection.has_inverse? && @reflection.inverse_of.macro == :has_one
+        def invertible_for?(record)
+          inverse = inverse_reflection_for(record)
+          inverse && inverse.macro == :has_one
         end
 
-        def record_id(record)
-          record.send(@reflection.options[:primary_key] || :id)
+        def target_id
+          if @reflection.options[:primary_key]
+            @owner.send(@reflection.name).try(:id)
+          else
+            @owner[@reflection.foreign_key]
+          end
         end
 
-        def previous_record_id
-          @previous_record_id ||= if @reflection.options[:primary_key]
-                                    previous_record = @owner.send(@reflection.name)
-                                    previous_record.nil? ? nil : previous_record.id
-                                  else
-                                    @owner[@reflection.primary_key_name]
-                                  end
+        def stale_state
+          @owner[@reflection.foreign_key].to_s
         end
     end
   end
diff --git a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
index a0df860623..4f67b02d00 100644
--- a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
@@ -1,77 +1,33 @@
 module ActiveRecord
   # = Active Record Belongs To Polymorphic Association
   module Associations
-    class BelongsToPolymorphicAssociation < AssociationProxy #:nodoc:
-      def replace(record)
-        if record.nil?
-          @target = @owner[@reflection.primary_key_name] = @owner[@reflection.options[:foreign_type]] = nil
-        else
-          @target = (AssociationProxy === record ? record.target : record)
-
-          @owner[@reflection.primary_key_name] = record_id(record)
-          @owner[@reflection.options[:foreign_type]] = record.class.base_class.name.to_s
-
-          @updated = true
-        end
-
-        set_inverse_instance(record, @owner)
-        loaded
-        record
-      end
-
-      def updated?
-        @updated
-      end
-
+    class BelongsToPolymorphicAssociation < BelongsToAssociation #:nodoc:
       private
 
-        # NOTE - for now, we're only supporting inverse setting from belongs_to back onto
-        # has_one associations.
-        def we_can_set_the_inverse_on_this?(record)
-          if @reflection.has_inverse?
-            inverse_association = @reflection.polymorphic_inverse_of(record.class)
-            inverse_association && inverse_association.macro == :has_one
-          else
-            false
-          end
-        end
-
-        def set_inverse_instance(record, instance)
-          return if record.nil? || !we_can_set_the_inverse_on_this?(record)
-          inverse_relationship = @reflection.polymorphic_inverse_of(record.class)
-          if inverse_relationship
-            record.send(:"set_#{inverse_relationship.name}_target", instance)
-          end
+        def replace_keys(record)
+          super
+          @owner[@reflection.foreign_type] = record && record.class.base_class.name
         end
 
-        def construct_find_scope
-          { :conditions => conditions }
+        def different_target?(record)
+          super || record.class != target_klass
         end
 
-        def find_target
-          return nil if association_class.nil?
-
-          target = association_class.send(:with_scope, :find => @scope[:find]) do
-            association_class.find(
-              @owner[@reflection.primary_key_name],
-              :select  => @reflection.options[:select],
-              :include => @reflection.options[:include]
-            )
-          end
-          set_inverse_instance(target, @owner)
-          target
+        def inverse_reflection_for(record)
+          @reflection.polymorphic_inverse_of(record.class)
         end
 
-        def foreign_key_present
-          !@owner[@reflection.primary_key_name].nil?
+        def target_klass
+          type = @owner[@reflection.foreign_type]
+          type && type.constantize
         end
 
-        def record_id(record)
-          record.send(@reflection.options[:primary_key] || :id)
+        def raise_on_type_mismatch(record)
+          # A polymorphic association cannot have a type mismatch, by definition
         end
 
-        def association_class
-          @owner[@reflection.options[:foreign_type]] ? @owner[@reflection.options[:foreign_type]].constantize : nil
+        def stale_state
+          [super, @owner[@reflection.foreign_type].to_s]
         end
     end
   end
diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency.rb
index a74d0a4ca8..fdd4fe8946 100644
--- a/activerecord/lib/active_record/associations/class_methods/join_dependency.rb
+++ b/activerecord/lib/active_record/associations/class_methods/join_dependency.rb
@@ -176,7 +176,7 @@ module ActiveRecord
 
             join_part = join_parts.detect { |j|
               j.reflection.name.to_s == name &&
-                j.parent_table_name    == parent.class.table_name }
+                j.parent_table_name == parent.class.table_name }
 
               raise(ConfigurationError, "No such association") unless join_part
 
@@ -201,7 +201,7 @@ module ActiveRecord
 
           macro = join_part.reflection.macro
           if macro == :has_one
-            return if record.instance_variable_defined?("@#{join_part.reflection.name}")
+            return if record.association_cache.key?(join_part.reflection.name)
             association = join_part.instantiate(row) unless row[join_part.aliased_primary_key].nil?
             set_target_and_inverse(join_part, association, record)
           else
@@ -210,9 +210,9 @@ module ActiveRecord
             case macro
             when :has_many, :has_and_belongs_to_many
               collection = record.send(join_part.reflection.name)
-              collection.loaded
+              collection.loaded!
               collection.target.push(association)
-              collection.__send__(:set_inverse_instance, association, record)
+              collection.send(:set_inverse_instance, association)
             when :belongs_to
               set_target_and_inverse(join_part, association, record)
             else
@@ -223,8 +223,9 @@ module ActiveRecord
         end
 
         def set_target_and_inverse(join_part, association, record)
-          association_proxy = record.send("set_#{join_part.reflection.name}_target", association)
-          association_proxy.__send__(:set_inverse_instance, association, record)
+          association_proxy = record.send(:association_proxy, join_part.reflection.name)
+          association_proxy.target = association
+          association_proxy.send(:set_inverse_instance, association)
         end
       end
     end
diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
index 694778008b..aaa475109e 100644
--- a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
+++ b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
@@ -82,12 +82,12 @@ module ActiveRecord
               connection = active_record.connection
 
               name = connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}"
-              table_index = aliases[name] + 1
-              name = name[0, connection.table_alias_length-3] + "_#{table_index}" if table_index > 1
+              aliases[name] += 1
+              name = name[0, connection.table_alias_length-3] + "_#{aliases[name]}" if aliases[name] > 1
+            else
+              aliases[name] += 1
             end
 
-            aliases[name] += 1
-
             name
           end
 
@@ -108,6 +108,10 @@ module ActiveRecord
           end
 
           def process_conditions(conditions, table_name)
+            if conditions.respond_to?(:to_proc)
+              conditions = instance_eval(&conditions)
+            end
+
             Arel.sql(sanitize_sql(conditions, table_name))
           end
 
@@ -190,17 +194,20 @@ module ActiveRecord
             ).alias @aliased_join_table_name
 
             jt_conditions = []
-            jt_foreign_key = first_key = second_key = nil
+            first_key = second_key = nil
 
-            if through_reflection.options[:as] # has_many :through against a polymorphic join
-              as_key         = through_reflection.options[:as].to_s
-              jt_foreign_key = as_key + '_id'
-
-              jt_conditions <<
-              join_table[as_key + '_type'].
-                eq(parent.active_record.base_class.name)
+            if through_reflection.macro == :belongs_to
+              jt_primary_key = through_reflection.foreign_key
+              jt_foreign_key = through_reflection.association_primary_key
             else
-              jt_foreign_key = through_reflection.primary_key_name
+              jt_primary_key = through_reflection.active_record_primary_key
+              jt_foreign_key = through_reflection.foreign_key
+
+              if through_reflection.options[:as] # has_many :through against a polymorphic join
+                jt_conditions <<
+                join_table["#{through_reflection.options[:as]}_type"].
+                  eq(parent.active_record.base_class.name)
+              end
             end
 
             case source_reflection.macro
@@ -225,15 +232,15 @@ module ActiveRecord
                 second_key = source_reflection.association_foreign_key
 
                 jt_conditions <<
-                join_table[reflection.source_reflection.options[:foreign_type]].
+                join_table[reflection.source_reflection.foreign_type].
                   eq(reflection.options[:source_type])
               else
-                second_key = source_reflection.primary_key_name
+                second_key = source_reflection.foreign_key
               end
             end
 
             jt_conditions <<
-            parent_table[parent.primary_key].
+            parent_table[jt_primary_key].
               eq(join_table[jt_foreign_key])
 
             if through_reflection.options[:conditions]
@@ -259,7 +266,7 @@ module ActiveRecord
           end
 
           def join_belongs_to_to(relation)
-            foreign_key = options[:foreign_key] || reflection.primary_key_name
+            foreign_key = options[:foreign_key] || reflection.foreign_key
             primary_key = options[:primary_key] || reflection.klass.primary_key
 
             join_target_table(
diff --git a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
index e2ce9aefcf..b9c9919e7a 100644
--- a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
@@ -2,81 +2,48 @@ module ActiveRecord
   # = Active Record Has And Belongs To Many Association
   module Associations
     class HasAndBelongsToManyAssociation < AssociationCollection #:nodoc:
-      def create(attributes = {})
-        create_record(attributes) { |record| insert_record(record) }
-      end
-
-      def create!(attributes = {})
-        create_record(attributes) { |record| insert_record(record, true) }
-      end
-
-      def columns
-        @reflection.columns(@reflection.options[:join_table], "#{@reflection.options[:join_table]} Columns")
-      end
-
-      def reset_column_information
-        @reflection.reset_column_information
-      end
+      attr_reader :join_table
 
-      def has_primary_key?
-        @has_primary_key ||= @owner.connection.supports_primary_key? && @owner.connection.primary_key(@reflection.options[:join_table])
+      def initialize(owner, reflection)
+        @join_table = Arel::Table.new(reflection.options[:join_table])
+        super
       end
 
       protected
-        def construct_find_options!(options)
-          options[:joins]      = Arel::SqlLiteral.new(@scope[:find][:joins])
-          options[:readonly]   = finding_with_ambiguous_select?(options[:select] || @reflection.options[:select])
-          options[:select]   ||= (@reflection.options[:select] || Arel::SqlLiteral.new('*'))
-        end
 
-        def count_records
-          load_target.size
-        end
-
-        def insert_record(record, force = true, validate = true)
-          if record.new_record?
-            if force
-              record.save!
-            else
-              return false unless record.save(:validate => validate)
-            end
-          end
+        def insert_record(record, validate = true)
+          return if record.new_record? && !record.save(:validate => validate)
 
           if @reflection.options[:insert_sql]
-            @owner.connection.insert(interpolate_sql(@reflection.options[:insert_sql], record))
+            @owner.connection.insert(interpolate(@reflection.options[:insert_sql], record))
           else
-            relation   = Arel::Table.new(@reflection.options[:join_table])
-            timestamps = record_timestamp_columns(record)
-            timezone   = record.send(:current_time_from_proper_timezone) if timestamps.any?
-
-            attributes = columns.map do |column|
-              name = column.name
-              value = case name.to_s
-                when @reflection.primary_key_name.to_s
-                  @owner.id
-                when @reflection.association_foreign_key.to_s
-                  record.id
-                when *timestamps
-                  timezone
-                else
-                  @owner.send(:quote_value, record[name], column) if record.has_attribute?(name)
-              end
-              [relation[name], value] unless value.nil?
-            end
-
-            stmt = relation.compile_insert Hash[attributes]
+            stmt = join_table.compile_insert(
+              join_table[@reflection.foreign_key]             => @owner.id,
+              join_table[@reflection.association_foreign_key] => record.id
+            )
+
             @owner.connection.insert stmt.to_sql
           end
 
-          true
+          record
         end
 
-        def delete_records(records)
+        def association_scope
+          super.joins(construct_joins)
+        end
+
+      private
+
+        def count_records
+          load_target.size
+        end
+
+        def delete_records(records, method)
           if sql = @reflection.options[:delete_sql]
-            records.each { |record| @owner.connection.delete(interpolate_sql(sql, record)) }
+            records.each { |record| @owner.connection.delete(interpolate(sql, record)) }
           else
-            relation = Arel::Table.new(@reflection.options[:join_table])
-            stmt = relation.where(relation[@reflection.primary_key_name].eq(@owner.id).
+            relation = join_table
+            stmt = relation.where(relation[@reflection.foreign_key].eq(@owner.id).
               and(relation[@reflection.association_foreign_key].in(records.map { |x| x.id }.compact))
             ).compile_delete
             @owner.connection.delete stmt.to_sql
@@ -84,51 +51,25 @@ module ActiveRecord
         end
 
         def construct_joins
-          "INNER JOIN #{@owner.connection.quote_table_name @reflection.options[:join_table]} ON #{@reflection.quoted_table_name}.#{@reflection.klass.primary_key} = #{@owner.connection.quote_table_name @reflection.options[:join_table]}.#{@reflection.association_foreign_key}"
-        end
+          right = join_table
+          left  = @reflection.klass.arel_table
 
-        def construct_conditions
-          sql = "#{@owner.connection.quote_table_name @reflection.options[:join_table]}.#{@reflection.primary_key_name} = #{owner_quoted_id} "
-          sql << " AND (#{conditions})" if conditions
-          sql
-        end
+          condition = left[@reflection.klass.primary_key].eq(
+            right[@reflection.association_foreign_key])
 
-        def construct_find_scope
-          {
-            :conditions => construct_conditions,
-            :joins      => construct_joins,
-            :readonly   => false,
-            :order      => @reflection.options[:order],
-            :include    => @reflection.options[:include],
-            :limit      => @reflection.options[:limit]
-          }
+          right.create_join(right, right.create_on(condition))
         end
 
-        # Join tables with additional columns on top of the two foreign keys must be considered
-        # ambiguous unless a select clause has been explicitly defined. Otherwise you can get
-        # broken records back, if, for example, the join column also has an id column. This will
-        # then overwrite the id column of the records coming back.
-        def finding_with_ambiguous_select?(select_clause)
-          !select_clause && columns.size != 2
+        def construct_owner_conditions
+          super(join_table)
         end
 
-      private
-        def create_record(attributes, &block)
-          # Can't use Base.create because the foreign key may be a protected attribute.
-          ensure_owner_is_persisted!
-          if attributes.is_a?(Array)
-            attributes.collect { |attr| create(attr) }
-          else
-            build_record(attributes, &block)
-          end
+        def select_value
+          super || @reflection.klass.arel_table[Arel.star]
         end
 
-        def record_timestamp_columns(record)
-          if record.record_timestamps
-            record.send(:all_timestamp_attributes).map { |x| x.to_s }
-          else
-            []
-          end
+        def invertible_for?(record)
+          false
         end
     end
   end
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index 4ff61fff45..543b073393 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -7,14 +7,14 @@ module ActiveRecord
     # is provided by its child HasManyThroughAssociation.
     class HasManyAssociation < AssociationCollection #:nodoc:
       protected
-        def owner_quoted_id
-          if @reflection.options[:primary_key]
-            @owner.class.quote_value(@owner.send(@reflection.options[:primary_key]))
-          else
-            @owner.quoted_id
-          end
+
+        def insert_record(record, validate = true)
+          set_owner_attributes(record)
+          record.save(:validate => validate)
         end
 
+      private
+
         # Returns the number of records in this collection.
         #
         # If the association has a counter cache it gets that value. Otherwise
@@ -34,83 +34,69 @@ module ActiveRecord
           elsif @reflection.options[:counter_sql] || @reflection.options[:finder_sql]
             @reflection.klass.count_by_sql(custom_counter_sql)
           else
-            @reflection.klass.count(@scope[:find].slice(:conditions, :joins, :include))
+            scoped.count
           end
 
           # If there's nothing in the database and @target has no new records
           # we are certain the current target is an empty array. This is a
           # documented side-effect of the method that may avoid an extra SELECT.
-          @target ||= [] and loaded if count == 0
+          @target ||= [] and loaded! if count == 0
 
           [@reflection.options[:limit], count].compact.min
         end
 
-        def has_cached_counter?
-          @owner.attribute_present?(cached_counter_attribute_name)
-        end
-
-        def cached_counter_attribute_name
-          "#{@reflection.name}_count"
+        def has_cached_counter?(reflection = @reflection)
+          @owner.attribute_present?(cached_counter_attribute_name(reflection))
         end
 
-        def insert_record(record, force = false, validate = true)
-          set_belongs_to_association_for(record)
-          force ? record.save! : record.save(:validate => validate)
+        def cached_counter_attribute_name(reflection = @reflection)
+          "#{reflection.name}_count"
         end
 
-        # Deletes the records according to the <tt>:dependent</tt> option.
-        def delete_records(records)
-          case @reflection.options[:dependent]
-            when :destroy
-              records.each { |r| r.destroy }
-            when :delete_all
-              @reflection.klass.delete(records.map { |record| record.id })
-            else
-              relation = Arel::Table.new(@reflection.table_name)
-              stmt = relation.where(relation[@reflection.primary_key_name].eq(@owner.id).
-                  and(relation[@reflection.klass.primary_key].in(records.map { |r| r.id }))
-              ).compile_update(relation[@reflection.primary_key_name] => nil)
-              @owner.connection.update stmt.to_sql
-
-              @owner.class.update_counters(@owner.id, cached_counter_attribute_name => -records.size) if has_cached_counter?
+        def update_counter(difference, reflection = @reflection)
+          if has_cached_counter?(reflection)
+            counter = cached_counter_attribute_name(reflection)
+            @owner.class.update_counters(@owner.id, counter => difference)
+            @owner[counter] += difference
+            @owner.changed_attributes.delete(counter) # eww
           end
         end
 
-        def target_obsolete?
-          false
+        # This shit is nasty. We need to avoid the following situation:
+        #
+        #   * An associated record is deleted via record.destroy
+        #   * Hence the callbacks run, and they find a belongs_to on the record with a
+        #     :counter_cache options which points back at our @owner. So they update the
+        #     counter cache.
+        #   * In which case, we must make sure to *not* update the counter cache, or else
+        #     it will be decremented twice.
+        #
+        # Hence this method.
+        def inverse_updates_counter_cache?(reflection = @reflection)
+          counter_name = cached_counter_attribute_name(reflection)
+          reflection.klass.reflect_on_all_associations(:belongs_to).any? { |inverse_reflection|
+            inverse_reflection.counter_cache_column == counter_name
+          }
         end
 
-        def construct_conditions
-          if @reflection.options[:as]
-            sql =
-              "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_id = #{owner_quoted_id} AND " +
-              "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote_value(@owner.class.base_class.name.to_s)}"
+        # Deletes the records according to the <tt>:dependent</tt> option.
+        def delete_records(records, method)
+          if method == :destroy
+            records.each { |r| r.destroy }
+            update_counter(-records.length) unless inverse_updates_counter_cache?
           else
-            sql = "#{@reflection.quoted_table_name}.#{@reflection.primary_key_name} = #{owner_quoted_id}"
-          end
-          sql << " AND (#{conditions})" if conditions
-          sql
-        end
-
-        def construct_find_scope
-          {
-            :conditions => construct_conditions,
-            :readonly   => false,
-            :order      => @reflection.options[:order],
-            :limit      => @reflection.options[:limit],
-            :include    => @reflection.options[:include]
-          }
-        end
+            keys  = records.map { |r| r[@reflection.association_primary_key] }
+            scope = scoped.where(@reflection.association_primary_key => keys)
 
-        def construct_create_scope
-          create_scoping = {}
-          set_belongs_to_association_for(create_scoping)
-          create_scoping
+            if method == :delete_all
+              update_counter(-scope.delete_all)
+            else
+              update_counter(-scope.update_all(@reflection.foreign_key => nil))
+            end
+          end
         end
 
-        def we_can_set_the_inverse_on_this?(record)
-          @reflection.inverse_of
-        end
+        alias creation_attributes construct_owner_attributes
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index 781aa7ef62..9f74d57c4d 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -1,82 +1,89 @@
-require "active_record/associations/through_association_scope"
 require 'active_support/core_ext/object/blank'
 
 module ActiveRecord
   # = Active Record Has Many Through Association
   module Associations
     class HasManyThroughAssociation < HasManyAssociation #:nodoc:
-      include ThroughAssociationScope
+      include ThroughAssociation
 
       alias_method :new, :build
 
-      def create!(attrs = nil)
-        create_record(attrs, true)
-      end
-
-      def create(attrs = nil)
-        create_record(attrs, false)
-      end
-
-      def destroy(*records)
-        transaction do
-          delete_records(flatten_deeper(records))
-          super
-        end
-      end
-
       # Returns the size of the collection by executing a SELECT COUNT(*) query if the collection hasn't been
       # loaded and calling collection.size if it has. If it's more likely than not that the collection does
       # have a size larger than zero, and you need to fetch that collection afterwards, it'll take one fewer
       # SELECT query if you use #length.
       def size
-        return @owner.send(:read_attribute, cached_counter_attribute_name) if has_cached_counter?
-        return @target.size if loaded?
-        return count
+        if has_cached_counter?
+          @owner.send(:read_attribute, cached_counter_attribute_name)
+        elsif loaded?
+          @target.size
+        else
+          count
+        end
+      end
+
+      def <<(*records)
+        unless @owner.new_record?
+          records.flatten.each do |record|
+            raise_on_type_mismatch(record)
+            record.save! if record.new_record?
+          end
+        end
+
+        super
       end
 
       protected
-        def create_record(attrs, force = true)
-          ensure_owner_is_persisted!
 
-          transaction do
-            object = @reflection.klass.new(attrs)
-            add_record_to_target_with_callbacks(object) {|r| insert_record(object, force) }
-            object
-          end
+        def insert_record(record, validate = true)
+          return if record.new_record? && !record.save(:validate => validate)
+
+          through_association = @owner.send(@reflection.through_reflection.name)
+          through_association.create!(construct_join_attributes(record))
+
+          update_counter(1)
+          record
         end
 
+      private
+
         def target_reflection_has_associated_record?
-          if @reflection.through_reflection.macro == :belongs_to && @owner[@reflection.through_reflection.primary_key_name].blank?
+          if @reflection.through_reflection.macro == :belongs_to && @owner[@reflection.through_reflection.foreign_key].blank?
             false
           else
             true
           end
         end
 
-        def construct_find_options!(options)
-          options[:joins]   = [construct_joins] + Array.wrap(options[:joins])
-          options[:include] = @reflection.source_reflection.options[:include] if options[:include].nil? && @reflection.source_reflection.options[:include]
+        def update_through_counter?(method)
+          case method
+          when :destroy
+            !inverse_updates_counter_cache?(@reflection.through_reflection)
+          when :nullify
+            false
+          else
+            true
+          end
         end
 
-        def insert_record(record, force = true, validate = true)
-          if record.new_record?
-            if force
-              record.save!
-            else
-              return false unless record.save(:validate => validate)
-            end
-          end
+        def delete_records(records, method)
+          through = @owner.send(:association_proxy, @reflection.through_reflection.name)
+          scope   = through.scoped.where(construct_join_attributes(*records))
 
-          through_association = @owner.send(@reflection.through_reflection.name)
-          through_association.create!(construct_join_attributes(record))
-        end
+          case method
+          when :destroy
+            count = scope.destroy_all.length
+          when :nullify
+            count = scope.update_all(@reflection.source_reflection.foreign_key => nil)
+          else
+            count = scope.delete_all
+          end
 
-        # TODO - add dependent option support
-        def delete_records(records)
-          klass = @reflection.through_reflection.klass
-          records.each do |associate|
-            klass.delete_all(construct_join_attributes(associate))
+          if @reflection.through_reflection.macro == :has_many && update_through_counter?(method)
+            update_counter(-count, @reflection.through_reflection)
           end
+
+          update_counter(-count)
         end
 
         def find_target
@@ -84,16 +91,8 @@ module ActiveRecord
           scoped.all
         end
 
-        def has_cached_counter?
-          @owner.attribute_present?(cached_counter_attribute_name)
-        end
-
-        def cached_counter_attribute_name
-          "#{@reflection.name}_count"
-        end
-
         # NOTE - not sure that we can actually cope with inverses here
-        def we_can_set_the_inverse_on_this?(record)
+        def invertible_for?(record)
           false
         end
     end
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index c49fd6e66a..a0828dcdea 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -1,135 +1,65 @@
 module ActiveRecord
   # = Active Record Belongs To Has One Association
   module Associations
-    class HasOneAssociation < AssociationProxy #:nodoc:
-      def create(attrs = {}, replace_existing = true)
-        new_record(replace_existing) do |reflection|
-          attrs = merge_with_conditions(attrs)
-          reflection.create_association(attrs)
-        end
-      end
-
-      def create!(attrs = {}, replace_existing = true)
-        new_record(replace_existing) do |reflection|
-          attrs = merge_with_conditions(attrs)
-          reflection.create_association!(attrs)
-        end
-      end
+    class HasOneAssociation < SingularAssociation #:nodoc:
+      def replace(record, save = true)
+        record = check_record(record)
+        load_target
 
-      def build(attrs = {}, replace_existing = true)
-        new_record(replace_existing) do |reflection|
-          attrs = merge_with_conditions(attrs)
-          reflection.build_association(attrs)
-        end
-      end
+        @reflection.klass.transaction do
+          if @target && @target != record
+            remove_target!(@reflection.options[:dependent])
+          end
 
-      def replace(obj, dont_save = false)
-        load_target
+          if record
+            set_inverse_instance(record)
+            set_owner_attributes(record)
 
-        unless @target.nil? || @target == obj
-          if dependent? && !dont_save
-            case @reflection.options[:dependent]
-            when :delete
-              @target.delete if @target.persisted?
-              @owner.clear_association_cache
-            when :destroy
-              @target.destroy if @target.persisted?
-              @owner.clear_association_cache
-            when :nullify
-              @target[@reflection.primary_key_name] = nil
-              @target.save if @owner.persisted? && @target.persisted?
+            if @owner.persisted? && save && !record.save
+              nullify_owner_attributes(record)
+              set_owner_attributes(@target)
+              raise RecordNotSaved, "Failed to save the new associated #{@reflection.name}."
             end
-          else
-            @target[@reflection.primary_key_name] = nil
-            @target.save if @owner.persisted? && @target.persisted?
           end
         end
 
-        if obj.nil?
-          @target = nil
-        else
-          raise_on_type_mismatch(obj)
-          set_belongs_to_association_for(obj)
-          @target = (AssociationProxy === obj ? obj.target : obj)
-        end
-
-        set_inverse_instance(obj, @owner)
-        @loaded = true
-
-        unless !@owner.persisted? || obj.nil? || dont_save
-          return (obj.save ? self : false)
-        else
-          return (obj.nil? ? nil : self)
-        end
+        self.target = record
       end
 
       protected
-        def owner_quoted_id
-          if @reflection.options[:primary_key]
-            @owner.class.quote_value(@owner.send(@reflection.options[:primary_key]))
-          else
-            @owner.quoted_id
-          end
+
+        def association_scope
+          super.order(@reflection.options[:order])
         end
 
       private
-        def find_target
-          options = @reflection.options.dup.slice(:select, :order, :include, :readonly)
-
-          the_target = with_scope(:find => @scope[:find]) do
-            @reflection.klass.find(:first, options)
-          end
-          set_inverse_instance(the_target, @owner)
-          the_target
-        end
 
-        def construct_find_scope
-          if @reflection.options[:as]
-            sql =
-              "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_id = #{owner_quoted_id} AND " +
-              "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote_value(@owner.class.base_class.name.to_s)}"
-          else
-            sql = "#{@reflection.quoted_table_name}.#{@reflection.primary_key_name} = #{owner_quoted_id}"
-          end
-          sql << " AND (#{conditions})" if conditions
-          { :conditions => sql }
-        end
+        alias creation_attributes construct_owner_attributes
 
-        def construct_create_scope
-          create_scoping = {}
-          set_belongs_to_association_for(create_scoping)
-          create_scoping
+        # The reason that the save param for replace is false, if for create (not just build),
+        # is because the setting of the foreign keys is actually handled by the scoping when
+        # the record is instantiated, and so they are set straight away and do not need to be
+        # updated within replace.
+        def set_new_record(record)
+          replace(record, false)
         end
 
-        def new_record(replace_existing)
-          # Make sure we load the target first, if we plan on replacing the existing
-          # instance. Otherwise, if the target has not previously been loaded
-          # elsewhere, the instance we create will get orphaned.
-          load_target if replace_existing
-          record = @reflection.klass.send(:with_scope, :create => @scope[:create]) do
-            yield @reflection
-          end
-
-          if replace_existing
-            replace(record, true)
+        def remove_target!(method)
+          if [:delete, :destroy].include?(method)
+            @target.send(method)
           else
-            record[@reflection.primary_key_name] = @owner.id if @owner.persisted?
-            self.target = record
-            set_inverse_instance(record, @owner)
-          end
+            nullify_owner_attributes(@target)
 
-          record
-        end
-
-        def we_can_set_the_inverse_on_this?(record)
-          inverse = @reflection.inverse_of
-          return !inverse.nil?
+            if @target.persisted? && @owner.persisted? && !@target.save
+              set_owner_attributes(@target)
+              raise RecordNotSaved, "Failed to remove the existing associated #{@reflection.name}. " +
+                                    "The record failed to save when after its foreign key was set to nil."
+            end
+          end
         end
 
-        def merge_with_conditions(attrs={})
-          attrs ||= {}
-          attrs.update(@reflection.options[:conditions]) if @reflection.options[:conditions].is_a?(Hash)
-          attrs
+        def nullify_owner_attributes(record)
+          record[@reflection.foreign_key] = nil
         end
     end
   end
diff --git a/activerecord/lib/active_record/associations/has_one_through_association.rb b/activerecord/lib/active_record/associations/has_one_through_association.rb
index e8cf73976b..69771afe50 100644
--- a/activerecord/lib/active_record/associations/has_one_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_through_association.rb
@@ -1,40 +1,34 @@
-require "active_record/associations/through_association_scope"
-
 module ActiveRecord
   # = Active Record Has One Through Association
   module Associations
     class HasOneThroughAssociation < HasOneAssociation
-      include ThroughAssociationScope
+      include ThroughAssociation
 
-      def replace(new_value)
-        create_through_record(new_value)
-        @target = new_value
+      def replace(record)
+        create_through_record(record)
+        self.target = record
       end
 
       private
 
-      def create_through_record(new_value) #nodoc:
-        klass = @reflection.through_reflection.klass
+        def create_through_record(record)
+          through_proxy  = @owner.send(:association_proxy, @reflection.through_reflection.name)
+          through_record = through_proxy.send(:load_target)
 
-        current_object = @owner.send(@reflection.through_reflection.name)
+          if through_record && !record
+            through_record.destroy
+          elsif record
+            attributes = construct_join_attributes(record)
 
-        if current_object
-           new_value ? current_object.update_attributes(construct_join_attributes(new_value)) : current_object.destroy
-        elsif new_value
-          if @owner.new_record?
-            self.target = new_value
-            through_association = @owner.send(:association_instance_get, @reflection.through_reflection.name)
-            through_association.build(construct_join_attributes(new_value))
-          else
-            @owner.send(@reflection.through_reflection.name, klass.create(construct_join_attributes(new_value)))
+            if through_record
+              through_record.update_attributes(attributes)
+            elsif @owner.new_record?
+              through_proxy.build(attributes)
+            else
+              through_proxy.create(attributes)
+            end
           end
         end
-      end
-
-    private
-      def find_target
-        scoped.first
-      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations/singular_association.rb b/activerecord/lib/active_record/associations/singular_association.rb
new file mode 100644
index 0000000000..7f92d9712a
--- /dev/null
+++ b/activerecord/lib/active_record/associations/singular_association.rb
@@ -0,0 +1,45 @@
+module ActiveRecord
+  module Associations
+    class SingularAssociation < AssociationProxy #:nodoc:
+      def create(attributes = {})
+        new_record(:create, attributes)
+      end
+
+      def create!(attributes = {})
+        build(attributes).tap { |record| record.save! }
+      end
+
+      def build(attributes = {})
+        new_record(:build, attributes)
+      end
+
+      private
+
+        def find_target
+          scoped.first.tap { |record| set_inverse_instance(record) }
+        end
+
+        # Implemented by subclasses
+        def replace(record)
+          raise NotImplementedError
+        end
+
+        def set_new_record(record)
+          replace(record)
+        end
+
+        def check_record(record)
+          record = record.target if AssociationProxy === record
+          raise_on_type_mismatch(record) if record
+          record
+        end
+
+        def new_record(method, attributes)
+          attributes = scoped.scope_for_create.merge(attributes || {})
+          record = @reflection.send("#{method}_association", attributes)
+          set_new_record(record)
+          record
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/through_association.rb b/activerecord/lib/active_record/associations/through_association.rb
new file mode 100644
index 0000000000..0550bae408
--- /dev/null
+++ b/activerecord/lib/active_record/associations/through_association.rb
@@ -0,0 +1,156 @@
+module ActiveRecord
+  # = Active Record Through Association
+  module Associations
+    module ThroughAssociation
+
+      protected
+
+        def target_scope
+          super.merge(@reflection.through_reflection.klass.scoped)
+        end
+
+        def association_scope
+          scope = super.joins(construct_joins)
+          scope = add_conditions(scope)
+          unless @reflection.options[:include]
+            scope = scope.includes(@reflection.source_reflection.options[:include])
+          end
+          scope
+        end
+
+      private
+
+        # This scope affects the creation of the associated records (not the join records). At the
+        # moment we only support creating on a :through association when the source reflection is a
+        # belongs_to. Thus it's not necessary to set a foreign key on the associated record(s), so
+        # this scope has can legitimately be empty.
+        def creation_attributes
+          { }
+        end
+
+        def aliased_through_table
+          name = @reflection.through_reflection.table_name
+
+          @reflection.table_name == name ?
+            @reflection.through_reflection.klass.arel_table.alias(name + "_join") :
+            @reflection.through_reflection.klass.arel_table
+        end
+
+        def construct_owner_conditions
+          super(aliased_through_table, @reflection.through_reflection)
+        end
+
+        def construct_joins
+          right = aliased_through_table
+          left  = @reflection.klass.arel_table
+
+          conditions = []
+
+          if @reflection.source_reflection.macro == :belongs_to
+            reflection_primary_key = @reflection.source_reflection.association_primary_key
+            source_primary_key     = @reflection.source_reflection.foreign_key
+
+            if @reflection.options[:source_type]
+              column = @reflection.source_reflection.foreign_type
+              conditions <<
+                right[column].eq(@reflection.options[:source_type])
+            end
+          else
+            reflection_primary_key = @reflection.source_reflection.foreign_key
+            source_primary_key     = @reflection.source_reflection.active_record_primary_key
+
+            if @reflection.source_reflection.options[:as]
+              column = "#{@reflection.source_reflection.options[:as]}_type"
+              conditions <<
+                left[column].eq(@reflection.through_reflection.klass.name)
+            end
+          end
+
+          conditions <<
+            left[reflection_primary_key].eq(right[source_primary_key])
+
+          right.create_join(
+            right,
+            right.create_on(right.create_and(conditions)))
+        end
+
+        # Construct attributes for :through pointing to owner and associate. This is used by the
+        # methods which create and delete records on the association.
+        #
+        # We only support indirectly modifying through associations which has a belongs_to source.
+        # This is the "has_many :tags, :through => :taggings" situation, where the join model
+        # typically has a belongs_to on both side. In other words, associations which could also
+        # be represented as has_and_belongs_to_many associations.
+        #
+        # We do not support creating/deleting records on the association where the source has
+        # some other type, because this opens up a whole can of worms, and in basically any
+        # situation it is more natural for the user to just create or modify their join records
+        # directly as required.
+        def construct_join_attributes(*records)
+          if @reflection.source_reflection.macro != :belongs_to
+            raise HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(@owner, @reflection)
+          end
+
+          join_attributes = {
+            @reflection.source_reflection.foreign_key =>
+              records.map { |record|
+                record.send(@reflection.source_reflection.association_primary_key)
+              }
+          }
+
+          if @reflection.options[:source_type]
+            join_attributes[@reflection.source_reflection.foreign_type] =
+              records.map { |record| record.class.base_class.name }
+          end
+
+          if records.count == 1
+            Hash[join_attributes.map { |k, v| [k, v.first] }]
+          else
+            join_attributes
+          end
+        end
+
+        # The reason that we are operating directly on the scope here (rather than passing
+        # back some arel conditions to be added to the scope) is because scope.where([x, y])
+        # has a different meaning to scope.where(x).where(y) - the first version might
+        # perform some substitution if x is a string.
+        def add_conditions(scope)
+          unless @reflection.through_reflection.klass.descends_from_active_record?
+            scope = scope.where(@reflection.through_reflection.klass.send(:type_condition))
+          end
+
+          scope = scope.where(interpolate(@reflection.source_reflection.options[:conditions]))
+          scope.where(through_conditions)
+        end
+
+        # If there is a hash of conditions then we make sure the keys are scoped to the
+        # through table name if left ambiguous.
+        def through_conditions
+          conditions = interpolate(@reflection.through_reflection.options[:conditions])
+
+          if conditions.is_a?(Hash)
+            Hash[conditions.map { |key, value|
+              unless value.is_a?(Hash) || key.to_s.include?('.')
+                key = aliased_through_table.name + '.' + key.to_s
+              end
+
+              [key, value]
+            }]
+          else
+            conditions
+          end
+        end
+
+        def stale_state
+          if @reflection.through_reflection.macro == :belongs_to
+            @owner[@reflection.through_reflection.foreign_key].to_s
+          end
+        end
+
+        def foreign_key_present?
+          @reflection.through_reflection.macro == :belongs_to &&
+          !@owner[@reflection.through_reflection.foreign_key].nil?
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/through_association_scope.rb b/activerecord/lib/active_record/associations/through_association_scope.rb
deleted file mode 100644
index 5dc5b0c048..0000000000
--- a/activerecord/lib/active_record/associations/through_association_scope.rb
+++ /dev/null
@@ -1,165 +0,0 @@
-module ActiveRecord
-  # = Active Record Through Association Scope
-  module Associations
-    module ThroughAssociationScope
-
-      def scoped
-        with_scope(@scope) do
-          @reflection.klass.scoped &
-          @reflection.through_reflection.klass.scoped
-        end
-      end
-
-      protected
-
-      def construct_find_scope
-        {
-          :conditions => construct_conditions,
-          :joins      => construct_joins,
-          :include    => @reflection.options[:include] || @reflection.source_reflection.options[:include],
-          :select     => construct_select,
-          :order      => @reflection.options[:order],
-          :limit      => @reflection.options[:limit],
-          :readonly   => @reflection.options[:readonly]
-        }
-      end
-
-      def construct_create_scope
-        construct_owner_attributes(@reflection)
-      end
-
-      def aliased_through_table
-        name = @reflection.through_reflection.table_name
-
-        @reflection.table_name == name ?
-          @reflection.through_reflection.klass.arel_table.alias(name + "_join") :
-          @reflection.through_reflection.klass.arel_table
-      end
-
-      # Build SQL conditions from attributes, qualified by table name.
-      def construct_conditions
-        table = aliased_through_table
-        conditions = construct_owner_attributes(@reflection.through_reflection).map do |attr, value|
-          table[attr].eq(value)
-        end
-        conditions << Arel.sql(sql_conditions) if sql_conditions
-        table.create_and(conditions)
-      end
-
-      # Associate attributes pointing to owner
-      def construct_owner_attributes(reflection)
-        if as = reflection.options[:as]
-          { "#{as}_id"   => @owner[reflection.active_record_primary_key],
-            "#{as}_type" => @owner.class.base_class.name }
-        elsif reflection.macro == :belongs_to
-          { reflection.klass.primary_key => @owner[reflection.primary_key_name] }
-        else
-          { reflection.primary_key_name => @owner[reflection.active_record_primary_key] }
-        end
-      end
-
-      def construct_from
-        @reflection.table_name
-      end
-
-      def construct_select(custom_select = nil)
-        distinct = "DISTINCT " if @reflection.options[:uniq]
-        custom_select || @reflection.options[:select] || "#{distinct}#{@reflection.quoted_table_name}.*"
-      end
-
-      def construct_joins
-        right = aliased_through_table
-        left  = @reflection.klass.arel_table
-
-        conditions = []
-
-        if @reflection.source_reflection.macro == :belongs_to
-          reflection_primary_key = @reflection.source_reflection.options[:primary_key] ||
-                                   @reflection.klass.primary_key
-          source_primary_key     = @reflection.source_reflection.primary_key_name
-          if @reflection.options[:source_type]
-            column = @reflection.source_reflection.options[:foreign_type]
-            conditions <<
-              right[column].eq(@reflection.options[:source_type])
-          end
-        else
-          reflection_primary_key = @reflection.source_reflection.primary_key_name
-          source_primary_key     = @reflection.source_reflection.options[:primary_key] ||
-                                   @reflection.through_reflection.klass.primary_key
-          if @reflection.source_reflection.options[:as]
-            column = "#{@reflection.source_reflection.options[:as]}_type"
-            conditions <<
-              left[column].eq(@reflection.through_reflection.klass.name)
-          end
-        end
-
-        conditions <<
-          left[reflection_primary_key].eq(right[source_primary_key])
-
-        right.create_join(
-          right,
-          right.create_on(right.create_and(conditions)))
-      end
-
-      # Construct attributes for :through pointing to owner and associate.
-      def construct_join_attributes(associate)
-        # TODO: revisit this to allow it for deletion, supposing dependent option is supported
-        raise ActiveRecord::HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(@owner, @reflection) if [:has_one, :has_many].include?(@reflection.source_reflection.macro)
-
-        join_attributes = construct_owner_attributes(@reflection.through_reflection).merge(@reflection.source_reflection.primary_key_name => associate.id)
-
-        if @reflection.options[:source_type]
-          join_attributes.merge!(@reflection.source_reflection.options[:foreign_type] => associate.class.base_class.name)
-        end
-
-        if @reflection.through_reflection.options[:conditions].is_a?(Hash)
-          join_attributes.merge!(@reflection.through_reflection.options[:conditions])
-        end
-
-        join_attributes
-      end
-
-      def conditions
-        @conditions = build_conditions unless defined?(@conditions)
-        @conditions
-      end
-
-      def build_conditions
-        association_conditions = @reflection.options[:conditions]
-        through_conditions = build_through_conditions
-        source_conditions = @reflection.source_reflection.options[:conditions]
-        uses_sti = !@reflection.through_reflection.klass.descends_from_active_record?
-
-        if association_conditions || through_conditions || source_conditions || uses_sti
-          all = []
-
-          [association_conditions, source_conditions].each do |conditions|
-            all << interpolate_sql(sanitize_sql(conditions)) if conditions
-          end
-
-          all << through_conditions  if through_conditions
-          all << build_sti_condition if uses_sti
-
-          all.map { |sql| "(#{sql})" } * ' AND '
-        end
-      end
-
-      def build_through_conditions
-        conditions = @reflection.through_reflection.options[:conditions]
-        if conditions.is_a?(Hash)
-          interpolate_sql(@reflection.through_reflection.klass.send(:sanitize_sql, conditions)).gsub(
-            @reflection.quoted_table_name,
-            @reflection.through_reflection.quoted_table_name)
-        elsif conditions
-          interpolate_sql(sanitize_sql(conditions))
-        end
-      end
-
-      def build_sti_condition
-        @reflection.through_reflection.klass.send(:type_condition).to_sql
-      end
-
-      alias_method :sql_conditions, :conditions
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index 75ae06f5e9..fcdd31ddea 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -14,26 +14,37 @@ module ActiveRecord
         # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
         # primary_key_prefix_type setting, though.
         def primary_key
-          reset_primary_key
+          @primary_key ||= reset_primary_key
         end
 
         def reset_primary_key #:nodoc:
-          key = get_primary_key(base_class.name)
+          key = self == base_class ? get_primary_key(base_class.name) :
+            base_class.primary_key
+
           set_primary_key(key)
           key
         end
 
         def get_primary_key(base_name) #:nodoc:
-          key = 'id'
+          return 'id' unless base_name && !base_name.blank?
+
           case primary_key_prefix_type
-            when :table_name
-              key = base_name.to_s.foreign_key(false)
-            when :table_name_with_underscore
-              key = base_name.to_s.foreign_key
+          when :table_name
+            base_name.foreign_key(false)
+          when :table_name_with_underscore
+            base_name.foreign_key
+          else
+            if ActiveRecord::Base != self && connection.table_exists?(table_name)
+              connection.primary_key(table_name)
+            else
+              'id'
+            end
           end
-          key
         end
 
+        attr_accessor :original_primary_key
+        attr_writer :primary_key
+
         # Sets the name of the primary key column to use to the given value,
         # or (if the value is nil or false) to the value returned by the given
         # block.
@@ -42,9 +53,12 @@ module ActiveRecord
         #     set_primary_key "sysid"
         #   end
         def set_primary_key(value = nil, &block)
-          define_attr_method :primary_key, value, &block
+          @primary_key ||= ''
+          self.original_primary_key = @primary_key
+          value &&= value.to_s
+          connection_pool.primary_keys[table_name] = value
+          self.primary_key = block_given? ? instance_eval(&block) : value
         end
-        alias :primary_key= :set_primary_key
       end
     end
   end
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 506f6e878f..ab86d8bad1 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -20,7 +20,7 @@ module ActiveRecord
         # be cached. Usually caching only pays off for attributes with expensive conversion
         # methods, like time related columns (e.g. +created_at+, +updated_at+).
         def cache_attributes(*attribute_names)
-          attribute_names.each {|attr| cached_attributes << attr.to_s}
+          cached_attributes.merge attribute_names.map { |attr| attr.to_s }
         end
 
         # Returns the attributes which are cached. By default time related columns
@@ -39,7 +39,7 @@ module ActiveRecord
             if serialized_attributes.include?(attr_name)
               define_read_method_for_serialized_attribute(attr_name)
             else
-              define_read_method(attr_name.to_sym, attr_name, columns_hash[attr_name])
+              define_read_method(attr_name, attr_name, columns_hash[attr_name])
             end
 
             if attr_name == primary_key && attr_name != "id"
@@ -54,17 +54,17 @@ module ActiveRecord
 
           # Define read method for serialized attribute.
           def define_read_method_for_serialized_attribute(attr_name)
-            access_code = "@attributes_cache['#{attr_name}'] ||= unserialize_attribute('#{attr_name}')"
-            generated_attribute_methods.module_eval("def #{attr_name}; #{access_code}; end", __FILE__, __LINE__)
+            access_code = "@attributes_cache['#{attr_name}'] ||= @attributes['#{attr_name}']"
+            generated_attribute_methods.module_eval("def _#{attr_name}; #{access_code}; end; alias #{attr_name} _#{attr_name}", __FILE__, __LINE__)
           end
 
           # Define an attribute reader method.  Cope with nil column.
           def define_read_method(symbol, attr_name, column)
-            cast_code = column.type_cast_code('v') if column
-            access_code = cast_code ? "(v=@attributes['#{attr_name}']) && #{cast_code}" : "@attributes['#{attr_name}']"
+            cast_code = column.type_cast_code('v')
+            access_code = "(v=@attributes['#{attr_name}']) && #{cast_code}"
 
             unless attr_name.to_s == self.primary_key.to_s
-              access_code = access_code.insert(0, "missing_attribute('#{attr_name}', caller) unless @attributes.has_key?('#{attr_name}'); ")
+              access_code.insert(0, "missing_attribute('#{attr_name}', caller) unless @attributes.has_key?('#{attr_name}'); ")
             end
 
             if cache_attribute?(attr_name)
@@ -106,14 +106,10 @@ module ActiveRecord
 
       # Returns the unserialized object of the attribute.
       def unserialize_attribute(attr_name)
-        unserialized_object = object_from_yaml(@attributes[attr_name])
+        coder = self.class.serialized_attributes[attr_name]
+        unserialized_object = coder.load(@attributes[attr_name])
 
-        if unserialized_object.is_a?(self.class.serialized_attributes[attr_name]) || unserialized_object.nil?
-          @attributes.frozen? ? unserialized_object : @attributes[attr_name] = unserialized_object
-        else
-          raise SerializationTypeMismatch,
-            "#{attr_name} was supposed to be a #{self.class.serialized_attributes[attr_name]}, but was a #{unserialized_object.class.to_s}"
-        end
+        @attributes.frozen? ? unserialized_object : @attributes[attr_name] = unserialized_object
       end
 
       private
diff --git a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
index dc2785b6bf..76218d2a73 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -40,12 +40,13 @@ module ActiveRecord
           def define_method_attribute=(attr_name)
             if create_time_zone_conversion_attribute?(attr_name, columns_hash[attr_name])
               method_body, line = <<-EOV, __LINE__ + 1
-                def #{attr_name}=(time)
+                def #{attr_name}=(original_time)
+                  time = original_time.dup unless original_time.nil?
                   unless time.acts_like?(:time)
                     time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
                   end
                   time = time.in_time_zone rescue nil if time
-                  write_attribute(:#{attr_name}, time)
+                  write_attribute(:#{attr_name}, (time || original_time))
                 end
               EOV
               generated_attribute_methods.module_eval(method_body, __FILE__, line)
diff --git a/activerecord/lib/active_record/autosave_association.rb b/activerecord/lib/active_record/autosave_association.rb
index 2dd69bd12c..ec27fd2e63 100644
--- a/activerecord/lib/active_record/autosave_association.rb
+++ b/activerecord/lib/active_record/autosave_association.rb
@@ -321,27 +321,30 @@ module ActiveRecord
 
         if records = associated_records_to_validate_or_save(association, @new_record_before_save, autosave)
           begin
-            records.each do |record|
-              next if record.destroyed?
-
-              if autosave && record.marked_for_destruction?
-                association.destroy(record)
-              elsif autosave != false && (@new_record_before_save || record.new_record?)
-                if autosave
-                  saved = association.send(:insert_record, record, false, false)
-                else
-                  association.send(:insert_record, record)
-                end
-              elsif autosave
-                saved = record.save(:validate => false)
+          records.each do |record|
+            next if record.destroyed?
+
+            saved = true
+
+            if autosave && record.marked_for_destruction?
+              association.destroy(record)
+            elsif autosave != false && (@new_record_before_save || record.new_record?)
+              if autosave
+                saved = association.send(:insert_record, record, false)
+              else
+                association.send(:insert_record, record)
               end
-
-              raise ActiveRecord::Rollback if saved == false
+            elsif autosave
+              saved = record.save(:validate => false)
             end
+
+            raise ActiveRecord::Rollback unless saved
+          end
           rescue
             records.each {|x| IdentityMap.remove(x) } if IdentityMap.enabled?
             raise
           end
+
         end
 
         # reconstruct the scope now that we know the owner's id
@@ -365,8 +368,8 @@ module ActiveRecord
           association.destroy
         else
           key = reflection.options[:primary_key] ? send(reflection.options[:primary_key]) : id
-          if autosave != false && (new_record? || association.new_record? || association[reflection.primary_key_name] != key || autosave)
-            association[reflection.primary_key_name] = key
+          if autosave != false && (new_record? || association.new_record? || association[reflection.foreign_key] != key || autosave)
+            association[reflection.foreign_key] = key
             saved = association.save(:validate => !autosave)
             raise ActiveRecord::Rollback if !saved && autosave
             saved
@@ -389,7 +392,8 @@ module ActiveRecord
 
           if association.updated?
             association_id = association.send(reflection.options[:primary_key] || :id)
-            self[reflection.primary_key_name] = association_id
+            self[reflection.foreign_key] = association_id
+            association.loaded!
           end
 
           saved if autosave
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 24c87662b8..01f5f4eccd 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1,3 +1,8 @@
+begin
+  require 'psych'
+rescue LoadError
+end
+
 require 'yaml'
 require 'set'
 require 'active_support/benchmarkable'
@@ -244,6 +249,17 @@ module ActiveRecord #:nodoc:
   #   user = User.create(:preferences => %w( one two three ))
   #   User.find(user.id).preferences    # raises SerializationTypeMismatch
   #
+  # When you specify a class option, the default value for that attribute will be a new
+  # instance of that class.
+  #
+  #   class User < ActiveRecord::Base
+  #     serialize :preferences, OpenStruct
+  #   end
+  #
+  #   user = User.new
+  #   user.preferences.theme_color = "red"
+  #
+  #
   # == Single table inheritance
   #
   # Active Record allows inheritance by storing the name of the class in a column that by
@@ -531,7 +547,15 @@ module ActiveRecord #:nodoc:
       #     serialize :preferences
       #   end
       def serialize(attr_name, class_name = Object)
-        serialized_attributes[attr_name.to_s] = class_name
+        coder = if [:load, :dump].all? { |x| class_name.respond_to?(x) }
+                  class_name
+                else
+                  Coders::YAMLColumn.new(class_name)
+                end
+
+        # merge new serialized attribute and create new hash to ensure that each class in inheritance hierarchy
+        # has its own hash of own serialized attributes
+        self.serialized_attributes = serialized_attributes.merge(attr_name.to_s => coder)
       end
 
       # Guesses the table name (in forced lower-case) based on the name of the class in the
@@ -614,6 +638,9 @@ module ActiveRecord #:nodoc:
       def set_table_name(value = nil, &block)
         @quoted_table_name = nil
         define_attr_method :table_name, value, &block
+
+        @arel_table = Arel::Table.new(table_name, :engine => arel_engine)
+        @relation = Relation.new(self, arel_table)
       end
       alias :table_name= :set_table_name
 
@@ -657,16 +684,12 @@ module ActiveRecord #:nodoc:
 
       # Returns an array of column objects for the table associated with this class.
       def columns
-        unless defined?(@columns) && @columns
-          @columns = connection.columns(table_name, "#{name} Columns")
-          @columns.each { |column| column.primary = column.name == primary_key }
-        end
-        @columns
+        connection_pool.columns[table_name]
       end
 
       # Returns a hash of column objects for the table associated with this class.
       def columns_hash
-        @columns_hash ||= Hash[columns.map { |column| [column.name, column] }]
+        connection_pool.columns_hash[table_name]
       end
 
       # Returns an array of column names as strings.
@@ -723,8 +746,14 @@ module ActiveRecord #:nodoc:
       def reset_column_information
         connection.clear_cache!
         undefine_attribute_methods
-        @column_names = @columns = @columns_hash = @content_columns = @dynamic_methods_hash = @inheritance_column = nil
-        @arel_engine = @relation = @arel_table = nil
+        connection_pool.clear_table_cache!(table_name) if table_exists?
+
+        @column_names = @content_columns = @dynamic_methods_hash = @inheritance_column = nil
+        @arel_engine = @relation = nil
+      end
+
+      def clear_cache! # :nodoc:
+        connection_pool.clear_cache!
       end
 
       def attribute_method?(attribute)
@@ -762,7 +791,7 @@ module ActiveRecord #:nodoc:
         :true == (@finder_needs_type_condition ||= descends_from_active_record? ? :false : :true)
       end
 
-      # Returns a string like 'Post id:integer, title:string, body:text'
+      # Returns a string like 'Post(id:integer, title:string, body:text)'
       def inspect
         if self == Base
           super
@@ -827,13 +856,13 @@ module ActiveRecord #:nodoc:
       end
 
       def arel_table
-        @arel_table ||= Arel::Table.new(table_name, arel_engine)
+        Arel::Table.new(table_name, arel_engine)
       end
 
       def arel_engine
         @arel_engine ||= begin
           if self == ActiveRecord::Base
-            Arel::Table.engine
+            ActiveRecord::Base
           else
             connection_handler.connection_pools[name] ? self : superclass.arel_engine
           end
@@ -874,35 +903,51 @@ module ActiveRecord #:nodoc:
         reset_scoped_methods
       end
 
-      private
+      # Specifies how the record is loaded by +Marshal+.
+      #
+      # +_load+ sets an instance variable for each key in the hash it takes as input.
+      # Override this method if you require more complex marshalling.
+      def _load(data)
+        record = allocate
+        record.init_with(Marshal.load(data))
+        record
+      end
 
-        def relation #:nodoc:
-          @relation ||= Relation.new(self, arel_table)
-          finder_needs_type_condition? ? @relation.where(type_condition) : @relation
-        end
 
-        # Finder methods must instantiate through this method to work with the
-        # single-table inheritance model that makes it possible to create
-        # objects of different types from the same table.
-        def instantiate(record)
-          sti_class = find_sti_class(record[inheritance_column])
-          record_id = sti_class.primary_key && record[sti_class.primary_key]
+      # Finder methods must instantiate through this method to work with the
+      # single-table inheritance model that makes it possible to create
+      # objects of different types from the same table.
+      def instantiate(record)
+        sti_class = find_sti_class(record[inheritance_column])
+        record_id = sti_class.primary_key && record[sti_class.primary_key]
 
-          if ActiveRecord::IdentityMap.enabled? && record_id
-            if (column = sti_class.columns_hash[sti_class.primary_key]) && column.number?
-              record_id = record_id.to_i
-            end
-            if instance = IdentityMap.get(sti_class, record_id)
-              instance.reinit_with('attributes' => record)
-            else
-              instance = sti_class.allocate.init_with('attributes' => record)
-              IdentityMap.add(instance)
-            end
+        if ActiveRecord::IdentityMap.enabled? && record_id
+          if (column = sti_class.columns_hash[sti_class.primary_key]) && column.number?
+            record_id = record_id.to_i
+          end
+          if instance = IdentityMap.get(sti_class, record_id)
+            instance.reinit_with('attributes' => record)
           else
             instance = sti_class.allocate.init_with('attributes' => record)
+            IdentityMap.add(instance)
           end
+        else
+          instance = sti_class.allocate.init_with('attributes' => record)
+        end
+
+        instance
+      end
 
-          instance
+      private
+
+        def relation #:nodoc:
+          @relation ||= Relation.new(self, arel_table)
+
+          if finder_needs_type_condition?
+            @relation.where(type_condition).create_with(inheritance_column.to_sym => sti_name)
+          else
+            @relation
+          end
         end
 
         def find_sti_class(type_name)
@@ -932,11 +977,10 @@ module ActiveRecord #:nodoc:
         end
 
         def type_condition
-          sti_column = arel_table[inheritance_column]
-          condition = sti_column.eq(sti_name)
-          descendants.each { |subclass| condition = condition.or(sti_column.eq(subclass.sti_name)) }
+          sti_column = arel_table[inheritance_column.to_sym]
+          sti_names  = ([self] + descendants).map { |model| model.sti_name }
 
-          condition
+          sti_column.in(sti_names)
         end
 
         # Guesses the table name, but does not decorate it with prefix and suffix information.
@@ -1383,6 +1427,8 @@ MSG
       # hence you can't have attributes that aren't part of the table columns.
       def initialize(attributes = nil)
         @attributes = attributes_from_column_definition
+        @association_cache = {}
+        @aggregation_cache = {}
         @attributes_cache = {}
         @new_record = true
         @readonly = false
@@ -1392,15 +1438,32 @@ MSG
         @changed_attributes = {}
 
         ensure_proper_type
+        set_serialized_attributes
 
         populate_with_current_scope_attributes
         self.attributes = attributes unless attributes.nil?
 
         result = yield self if block_given?
-        _run_initialize_callbacks
+        run_callbacks :initialize
         result
       end
 
+      # Populate +coder+ with attributes about this record that should be
+      # serialized.  The structure of +coder+ defined in this method is
+      # guaranteed to match the structure of +coder+ passed to the +init_with+
+      # method.
+      #
+      # Example:
+      #
+      #   class Post < ActiveRecord::Base
+      #   end
+      #   coder = {}
+      #   Post.new.encode_with(coder)
+      #   coder # => { 'id' => nil, ... }
+      def encode_with(coder)
+        coder['attributes'] = attributes
+      end
+
       # Initialize an empty model object from +coder+.  +coder+ must contain
       # the attributes necessary for initializing an empty model object.  For
       # example:
@@ -1413,15 +1476,30 @@ MSG
       #   post.title # => 'hello world'
       def init_with(coder)
         @attributes = coder['attributes']
+
+        set_serialized_attributes
+
         @attributes_cache, @previously_changed, @changed_attributes = {}, {}, {}
+        @association_cache = {}
+        @aggregation_cache = {}
         @readonly = @destroyed = @marked_for_destruction = false
         @new_record = false
-        _run_find_callbacks
-        _run_initialize_callbacks
+        run_callbacks :find
+        run_callbacks :initialize
 
         self
       end
 
+      # Specifies how the record is dumped by +Marshal+.
+      #
+      # +_dump+ emits a marshalled hash which has been passed to +encode_with+. Override this
+      # method if you require more complex marshalling.
+      def _dump(level)
+        dump = {}
+        encode_with(dump)
+        Marshal.dump(dump)
+      end
+
       # Returns a String, which Action Pack uses for constructing an URL to this
       # object. The default implementation returns this record's id as a String,
       # or nil if this record's unsaved.
@@ -1511,8 +1589,10 @@ MSG
         attributes.each do |k, v|
           if k.include?("(")
             multi_parameter_attributes << [ k, v ]
+          elsif respond_to?("#{k}=")
+            send("#{k}=", v)
           else
-            respond_to?(:"#{k}=") ? send(:"#{k}=", v) : raise(UnknownAttributeError, "unknown attribute: #{k}")
+            raise(UnknownAttributeError, "unknown attribute: #{k}")
           end
         end
 
@@ -1552,7 +1632,7 @@ MSG
       # Returns true if the specified +attribute+ has been set by the user or by a database load and is neither
       # nil nor empty? (the latter only applies to objects that respond to empty?, most notably Strings).
       def attribute_present?(attribute)
-        !read_attribute(attribute).blank?
+        !_read_attribute(attribute).blank?
       end
 
       # Returns the column object for the named attribute.
@@ -1625,9 +1705,9 @@ MSG
           @changed_attributes[attr] = orig_value if field_changed?(attr, orig_value, @attributes[attr])
         end
 
-        clear_aggregation_cache
-        clear_association_cache
-        @attributes_cache   = {}
+        @aggregation_cache = {}
+        @association_cache = {}
+        @attributes_cache = {}
         @new_record  = true
 
         ensure_proper_type
@@ -1649,7 +1729,7 @@ MSG
       # Returns the contents of the record as a nicely formatted string.
       def inspect
         attributes_as_nice_string = self.class.column_names.collect { |name|
-          if has_attribute?(name) || new_record?
+          if has_attribute?(name)
             "#{name}: #{attribute_for_inspect(name)}"
           end
         }.compact.join(", ")
@@ -1673,6 +1753,13 @@ MSG
 
     private
 
+      def set_serialized_attributes
+        (@attributes.keys & self.class.serialized_attributes.keys).each do |key|
+          coder = self.class.serialized_attributes[key]
+          @attributes[key] = coder.load @attributes[key]
+        end
+      end
+
       # Sets the attribute used for single table inheritance to this class name if this is not the
       # ActiveRecord::Base descendant.
       # Considering the hierarchy Reply < Message < ActiveRecord::Base, this makes it possible to
@@ -1694,17 +1781,25 @@ MSG
       # Returns a copy of the attributes hash where all the values have been safely quoted for use in
       # an Arel insert/update method.
       def arel_attributes_values(include_primary_key = true, include_readonly_attributes = true, attribute_names = @attributes.keys)
-        attrs = {}
+        attrs      = {}
+        klass      = self.class
+        arel_table = klass.arel_table
+
         attribute_names.each do |name|
           if (column = column_for_attribute(name)) && (include_primary_key || !column.primary)
 
             if include_readonly_attributes || (!include_readonly_attributes && !self.class.readonly_attributes.include?(name))
-              value = read_attribute(name)
 
-              if !value.nil? && self.class.serialized_attributes.key?(name)
-                value = YAML.dump value
-              end
-              attrs[self.class.arel_table[name]] = value
+              value = if coder = klass.serialized_attributes[name]
+                        coder.dump @attributes[name]
+                      else
+                        # FIXME: we need @attributes to be used consistently.
+                        # If the values stored in @attributes were already type
+                        # casted, this code could be simplified
+                        read_attribute(name)
+                      end
+
+              attrs[arel_table[name]] = value
             end
           end
         end
@@ -1716,12 +1811,6 @@ MSG
         self.class.connection.quote(value, column)
       end
 
-      # Interpolate custom SQL string in instance context.
-      # Optional record argument is meant for custom insert_sql.
-      def interpolate_sql(sql, record = nil)
-        instance_eval("%@#{sql.gsub('@', '\@')}@", __FILE__, __LINE__)
-      end
-
       # Instantiates objects for all attribute classes that needs more than one constructor parameter. This is done
       # by calling new on the column type or aggregation type (through composed_of) object with these parameters.
       # So having the pairs written_on(1) = "2004", written_on(2) = "6", written_on(3) = "24", will instantiate
@@ -1828,27 +1917,20 @@ MSG
         end
       end
 
-      def object_from_yaml(string)
-        return string unless string.is_a?(String) && string =~ /^---/
-        YAML::load(string) rescue string
-      end
-
       def populate_with_current_scope_attributes
         if scope = self.class.send(:current_scoped_methods)
           create_with = scope.scope_for_create
           create_with.each { |att,value|
-            respond_to?(:"#{att}=") && send("#{att}=", value)
+            respond_to?("#{att}=") && send("#{att}=", value)
           }
         end
       end
 
       # Clear attributes and changed_attributes
       def clear_timestamp_attributes
-        %w(created_at created_on updated_at updated_on).each do |attribute_name|
-          if has_attribute?(attribute_name)
-            self[attribute_name] = nil
-            changed_attributes.delete(attribute_name)
-          end
+        all_timestamp_attributes_in_model.each do |attribute_name|
+          self[attribute_name] = nil
+          changed_attributes.delete(attribute_name)
         end
       end
   end
diff --git a/activerecord/lib/active_record/callbacks.rb b/activerecord/lib/active_record/callbacks.rb
index 47428cfd0f..ff4ce1b605 100644
--- a/activerecord/lib/active_record/callbacks.rb
+++ b/activerecord/lib/active_record/callbacks.rb
@@ -25,9 +25,13 @@ module ActiveRecord
   # Check out <tt>ActiveRecord::Transactions</tt> for more details about <tt>after_commit</tt> and
   # <tt>after_rollback</tt>.
   #
-  # That's a total of ten callbacks, which gives you immense power to react and prepare for each state in the
+  # Lastly an <tt>after_find</tt> and <tt>after_initialize</tt> callback is triggered for each object that 
+  # is found and instantiated by a finder, with <tt>after_initialize</tt> being triggered after new objects
+  # are instantiated as well.
+  #
+  # That's a total of twelve callbacks, which gives you immense power to react and prepare for each state in the
   # Active Record life cycle. The sequence for calling <tt>Base#save</tt> for an existing record is similar,
-  # except that each <tt>_on_create</tt> callback is replaced by the corresponding <tt>_on_update</tt> callback.
+  # except that each <tt>_create</tt> callback is replaced by the corresponding <tt>_update</tt> callback.
   #
   # Examples:
   #   class CreditCard < ActiveRecord::Base
@@ -185,14 +189,6 @@ module ActiveRecord
   #                    'puts "Evaluated after parents are destroyed"'
   #   end
   #
-  # == The +after_find+ and +after_initialize+ exceptions
-  #
-  # Because +after_find+ and +after_initialize+ are called for each object found and instantiated by a finder,
-  # such as <tt>Base.find(:all)</tt>, we've had to implement a simple performance constraint (50% more speed
-  # on a simple test case). Unlike all the other callbacks, +after_find+ and +after_initialize+ will only be
-  # run if an explicit implementation is defined (<tt>def after_find</tt>). In that case, all of the
-  # callback types will be called.
-  #
   # == <tt>before_validation*</tt> returning statements
   #
   # If the returning value of a +before_validation+ callback can be evaluated to +false+, the process will be
@@ -237,25 +233,25 @@ module ActiveRecord
     end
 
     def destroy #:nodoc:
-      _run_destroy_callbacks { super }
+      run_callbacks(:destroy) { super }
     end
 
     def touch(*) #:nodoc:
-      _run_touch_callbacks { super }
+      run_callbacks(:touch) { super }
     end
 
   private
 
     def create_or_update #:nodoc:
-      _run_save_callbacks { super }
+      run_callbacks(:save) { super }
     end
 
     def create #:nodoc:
-      _run_create_callbacks { super }
+      run_callbacks(:create) { super }
     end
 
     def update(*) #:nodoc:
-      _run_update_callbacks { super }
+      run_callbacks(:update) { super }
     end
   end
 end
diff --git a/activerecord/lib/active_record/coders/yaml_column.rb b/activerecord/lib/active_record/coders/yaml_column.rb
new file mode 100644
index 0000000000..fb59d9fb07
--- /dev/null
+++ b/activerecord/lib/active_record/coders/yaml_column.rb
@@ -0,0 +1,41 @@
+module ActiveRecord
+  # :stopdoc:
+  module Coders
+    class YAMLColumn
+      RESCUE_ERRORS = [ ArgumentError ]
+
+      if defined?(Psych) && defined?(Psych::SyntaxError)
+        RESCUE_ERRORS << Psych::SyntaxError
+      end
+
+      attr_accessor :object_class
+
+      def initialize(object_class = Object)
+        @object_class = object_class
+      end
+
+      def dump(obj)
+        YAML.dump obj
+      end
+
+      def load(yaml)
+        return object_class.new if object_class != Object && yaml.nil?
+        return yaml unless yaml.is_a?(String) && yaml =~ /^---/
+        begin
+          obj = YAML.load(yaml)
+
+          unless obj.is_a?(object_class) || obj.nil?
+            raise SerializationTypeMismatch,
+              "Attribute was supposed to be a #{object_class}, but was a #{obj.class}"
+          end
+          obj ||= object_class.new if object_class != Object
+
+          obj
+        rescue *RESCUE_ERRORS
+          yaml
+        end
+      end
+    end
+  end
+  # :startdoc
+end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index cffa2387de..4297c26413 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -57,7 +57,9 @@ module ActiveRecord
     # * +wait_timeout+: number of seconds to block and wait for a connection
     #   before giving up and raising a timeout error (default 5 seconds).
     class ConnectionPool
+      attr_accessor :automatic_reconnect
       attr_reader :spec, :connections
+      attr_reader :columns, :columns_hash, :primary_keys, :tables
 
       # Creates a new ConnectionPool object. +spec+ is a ConnectionSpecification
       # object which describes database connection information (e.g. adapter,
@@ -81,6 +83,63 @@ module ActiveRecord
 
         @connections = []
         @checked_out = []
+        @automatic_reconnect = true
+        @tables = {}
+
+        @columns     = Hash.new do |h, table_name|
+          h[table_name] = with_connection do |conn|
+
+            # Fetch a list of columns
+            conn.columns(table_name, "#{table_name} Columns").tap do |columns|
+
+              # set primary key information
+              columns.each do |column|
+                column.primary = column.name == primary_keys[table_name]
+              end
+            end
+          end
+        end
+
+        @columns_hash = Hash.new do |h, table_name|
+          h[table_name] = Hash[columns[table_name].map { |col|
+            [col.name, col]
+          }]
+        end
+
+        @primary_keys = Hash.new do |h, table_name|
+          h[table_name] = with_connection do |conn|
+            table_exists?(table_name) ? conn.primary_key(table_name) : 'id'
+          end
+        end
+      end
+
+      # A cached lookup for table existence
+      def table_exists?(name)
+        return true if @tables.key? name
+
+        with_connection do |conn|
+          conn.tables.each { |table| @tables[table] = true }
+        end
+
+        @tables.key? name
+      end
+
+      # Clears out internal caches:
+      #
+      #   * columns
+      #   * columns_hash
+      #   * tables
+      def clear_cache!
+        @columns.clear
+        @columns_hash.clear
+        @tables.clear
+      end
+
+      # Clear out internal caches for table with +table_name+
+      def clear_table_cache!(table_name)
+        @columns.delete table_name
+        @columns_hash.delete table_name
+        @primary_keys.delete table_name
       end
 
       # Retrieve the connection associated with the current thread, or call
@@ -212,7 +271,7 @@ module ActiveRecord
       # calling +checkout+ on this pool.
       def checkin(conn)
         @connection_mutex.synchronize do
-          conn.send(:_run_checkin_callbacks) do
+          conn.run_callbacks :checkin do
             @checked_out.delete conn
             @queue.signal
           end
@@ -232,6 +291,8 @@ module ActiveRecord
       end
 
       def checkout_new_connection
+        raise ConnectionNotEstablished unless @automatic_reconnect
+
         c = new_connection
         @connections << c
         checkout_and_verify(c)
@@ -330,7 +391,7 @@ module ActiveRecord
         pool = @connection_pools[klass.name]
         return nil unless pool
 
-        @connection_pools.delete_if { |key, value| value == pool }
+        pool.automatic_reconnect = false
         pool.disconnect!
         pool.spec.config
       end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
index ee9a0af35c..5c1ce173c8 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -1,3 +1,5 @@
+require 'active_support/core_ext/module/deprecation'
+
 module ActiveRecord
   module ConnectionAdapters # :nodoc:
     module DatabaseStatements
@@ -229,6 +231,8 @@ module ActiveRecord
       #
       # This method *modifies* the +sql+ parameter.
       #
+      # This method is deprecated!! Stop using it!
+      #
       # ===== Examples
       #  add_limit_offset!('SELECT * FROM suppliers', {:limit => 10, :offset => 50})
       # generates
@@ -243,6 +247,7 @@ module ActiveRecord
         end
         sql
       end
+      deprecate :add_limit_offset!
 
       def default_sequence_name(table, column)
         nil
@@ -256,7 +261,15 @@ module ActiveRecord
       # Inserts the given fixture into the table. Overridden in adapters that require
       # something beyond a simple insert (eg. Oracle).
       def insert_fixture(fixture, table_name)
-        execute "INSERT INTO #{quote_table_name(table_name)} (#{fixture.key_list}) VALUES (#{fixture.value_list})", 'Fixture Insert'
+        columns = Hash[columns(table_name).map { |c| [c.name, c] }]
+
+        key_list   = []
+        value_list = fixture.map do |name, value|
+          key_list << quote_column_name(name)
+          quote(value, columns[name])
+        end
+
+        execute "INSERT INTO #{quote_table_name(table_name)} (#{key_list.join(', ')}) VALUES (#{value_list.join(', ')})", 'Fixture Insert'
       end
 
       def empty_insert_statement_value
@@ -271,6 +284,25 @@ module ActiveRecord
         "WHERE #{quoted_primary_key} IN (SELECT #{quoted_primary_key} FROM #{quoted_table_name} #{where_sql})"
       end
 
+      # Sanitizes the given LIMIT parameter in order to prevent SQL injection.
+      #
+      # The +limit+ may be anything that can evaluate to a string via #to_s. It
+      # should look like an integer, or a comma-delimited list of integers, or 
+      # an Arel SQL literal.
+      #
+      # Returns Integer and Arel::Nodes::SqlLiteral limits as is. 
+      # Returns the sanitized limit parameter, either as an integer, or as a
+      # string which contains a comma-delimited list of integers.
+      def sanitize_limit(limit)
+        if limit.is_a?(Integer) || limit.is_a?(Arel::Nodes::SqlLiteral)
+          limit
+        elsif limit.to_s =~ /,/
+          Arel.sql limit.to_s.split(',').map{ |i| Integer(i) }.join(',')
+        else
+          Integer(limit)
+        end
+      end
+
       protected
         # Returns an array of record hashes with the column names as keys and
         # column values as values.
@@ -294,21 +326,6 @@ module ActiveRecord
           update_sql(sql, name)
         end
 
-        # Sanitizes the given LIMIT parameter in order to prevent SQL injection.
-        #
-        # +limit+ may be anything that can evaluate to a string via #to_s. It
-        # should look like an integer, or a comma-delimited list of integers.
-        #
-        # Returns the sanitized limit parameter, either as an integer, or as a
-        # string which contains a comma-delimited list of integers.
-        def sanitize_limit(limit)
-          if limit.to_s =~ /,/
-            limit.to_s.split(',').map{ |i| i.to_i }.join(',')
-          else
-            limit.to_i
-          end
-        end
-
         # Send a rollback message to all records after they have been rolled back. If rollback
         # is false, only rollback records since the last save point.
         def rollback_transaction_records(rollback) #:nodoc
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
index d555308485..1db397f584 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
@@ -60,7 +60,7 @@ module ActiveRecord
           result =
             if @query_cache[sql].key?(binds)
               ActiveSupport::Notifications.instrument("sql.active_record",
-                :sql => sql, :name => "CACHE", :connection_id => self.object_id)
+                :sql => sql, :name => "CACHE", :connection_id => object_id)
               @query_cache[sql][binds]
             else
               @query_cache[sql][binds] = yield
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
index a7a12faac2..7489e88eef 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
@@ -33,8 +33,9 @@ module ActiveRecord
         when BigDecimal then value.to_s('F')
         when Numeric    then value.to_s
         when Date, Time then "'#{quoted_date(value)}'"
+        when Symbol     then "'#{quote_string(value.to_s)}'"
         else
-          "'#{quote_string(value.to_s)}'"
+          "'#{quote_string(value.to_yaml)}'"
         end
       end
 
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 60ccf9edf3..7ac48c6646 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -6,264 +6,6 @@ require 'bigdecimal/util'
 
 module ActiveRecord
   module ConnectionAdapters #:nodoc:
-    # An abstract definition of a column in a table.
-    class Column
-      TRUE_VALUES = [true, 1, '1', 't', 'T', 'true', 'TRUE'].to_set
-      FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE'].to_set
-
-      module Format
-        ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/
-        ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(\.\d+)?\z/
-      end
-
-      attr_reader :name, :default, :type, :limit, :null, :sql_type, :precision, :scale
-      attr_accessor :primary
-
-      # Instantiates a new column in the table.
-      #
-      # +name+ is the column's name, such as <tt>supplier_id</tt> in <tt>supplier_id int(11)</tt>.
-      # +default+ is the type-casted default value, such as +new+ in <tt>sales_stage varchar(20) default 'new'</tt>.
-      # +sql_type+ is used to extract the column's length, if necessary. For example +60+ in
-      # <tt>company_name varchar(60)</tt>.
-      # It will be mapped to one of the standard Rails SQL types in the <tt>type</tt> attribute.
-      # +null+ determines if this column allows +NULL+ values.
-      def initialize(name, default, sql_type = nil, null = true)
-        @name, @sql_type, @null = name, sql_type, null
-        @limit, @precision, @scale = extract_limit(sql_type), extract_precision(sql_type), extract_scale(sql_type)
-        @type = simplified_type(sql_type)
-        @default = extract_default(default)
-
-        @primary = nil
-      end
-
-      # Returns +true+ if the column is either of type string or text.
-      def text?
-        type == :string || type == :text
-      end
-
-      # Returns +true+ if the column is either of type integer, float or decimal.
-      def number?
-        type == :integer || type == :float || type == :decimal
-      end
-
-      def has_default?
-        !default.nil?
-      end
-
-      # Returns the Ruby class that corresponds to the abstract data type.
-      def klass
-        case type
-          when :integer       then Fixnum
-          when :float         then Float
-          when :decimal       then BigDecimal
-          when :datetime      then Time
-          when :date          then Date
-          when :timestamp     then Time
-          when :time          then Time
-          when :text, :string then String
-          when :binary        then String
-          when :boolean       then Object
-        end
-      end
-
-      # Casts value (which is a String) to an appropriate instance.
-      def type_cast(value)
-        return nil if value.nil?
-        case type
-          when :string    then value
-          when :text      then value
-          when :integer   then value.to_i rescue value ? 1 : 0
-          when :float     then value.to_f
-          when :decimal   then self.class.value_to_decimal(value)
-          when :datetime  then self.class.string_to_time(value)
-          when :timestamp then self.class.string_to_time(value)
-          when :time      then self.class.string_to_dummy_time(value)
-          when :date      then self.class.string_to_date(value)
-          when :binary    then self.class.binary_to_string(value)
-          when :boolean   then self.class.value_to_boolean(value)
-          else value
-        end
-      end
-
-      def type_cast_code(var_name)
-        case type
-          when :string    then nil
-          when :text      then nil
-          when :integer   then "(#{var_name}.to_i rescue #{var_name} ? 1 : 0)"
-          when :float     then "#{var_name}.to_f"
-          when :decimal   then "#{self.class.name}.value_to_decimal(#{var_name})"
-          when :datetime  then "#{self.class.name}.string_to_time(#{var_name})"
-          when :timestamp then "#{self.class.name}.string_to_time(#{var_name})"
-          when :time      then "#{self.class.name}.string_to_dummy_time(#{var_name})"
-          when :date      then "#{self.class.name}.string_to_date(#{var_name})"
-          when :binary    then "#{self.class.name}.binary_to_string(#{var_name})"
-          when :boolean   then "#{self.class.name}.value_to_boolean(#{var_name})"
-          else nil
-        end
-      end
-
-      # Returns the human name of the column name.
-      #
-      # ===== Examples
-      #  Column.new('sales_stage', ...).human_name # => 'Sales stage'
-      def human_name
-        Base.human_attribute_name(@name)
-      end
-
-      def extract_default(default)
-        type_cast(default)
-      end
-
-      # Used to convert from Strings to BLOBs
-      def string_to_binary(value)
-        self.class.string_to_binary(value)
-      end
-
-      class << self
-        # Used to convert from Strings to BLOBs
-        def string_to_binary(value)
-          value
-        end
-
-        # Used to convert from BLOBs to Strings
-        def binary_to_string(value)
-          value
-        end
-
-        def string_to_date(string)
-          return string unless string.is_a?(String)
-          return nil if string.empty?
-
-          fast_string_to_date(string) || fallback_string_to_date(string)
-        end
-
-        def string_to_time(string)
-          return string unless string.is_a?(String)
-          return nil if string.empty?
-
-          fast_string_to_time(string) || fallback_string_to_time(string)
-        end
-
-        def string_to_dummy_time(string)
-          return string unless string.is_a?(String)
-          return nil if string.empty?
-
-          string_to_time "2000-01-01 #{string}"
-        end
-
-        # convert something to a boolean
-        def value_to_boolean(value)
-          if value.is_a?(String) && value.blank?
-            nil
-          else
-            TRUE_VALUES.include?(value)
-          end
-        end
-
-        # convert something to a BigDecimal
-        def value_to_decimal(value)
-          # Using .class is faster than .is_a? and
-          # subclasses of BigDecimal will be handled
-          # in the else clause
-          if value.class == BigDecimal
-            value
-          elsif value.respond_to?(:to_d)
-            value.to_d
-          else
-            value.to_s.to_d
-          end
-        end
-
-        protected
-          # '0.123456' -> 123456
-          # '1.123456' -> 123456
-          def microseconds(time)
-            ((time[:sec_fraction].to_f % 1) * 1_000_000).to_i
-          end
-
-          def new_date(year, mon, mday)
-            if year && year != 0
-              Date.new(year, mon, mday) rescue nil
-            end
-          end
-
-          def new_time(year, mon, mday, hour, min, sec, microsec)
-            # Treat 0000-00-00 00:00:00 as nil.
-            return nil if year.nil? || year == 0
-
-            Time.time_with_datetime_fallback(Base.default_timezone, year, mon, mday, hour, min, sec, microsec) rescue nil
-          end
-
-          def fast_string_to_date(string)
-            if string =~ Format::ISO_DATE
-              new_date $1.to_i, $2.to_i, $3.to_i
-            end
-          end
-
-          # Doesn't handle time zones.
-          def fast_string_to_time(string)
-            if string =~ Format::ISO_DATETIME
-              microsec = ($7.to_f * 1_000_000).to_i
-              new_time $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, microsec
-            end
-          end
-
-          def fallback_string_to_date(string)
-            new_date(*::Date._parse(string, false).values_at(:year, :mon, :mday))
-          end
-
-          def fallback_string_to_time(string)
-            time_hash = Date._parse(string)
-            time_hash[:sec_fraction] = microseconds(time_hash)
-
-            new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction))
-          end
-      end
-
-      private
-        def extract_limit(sql_type)
-          $1.to_i if sql_type =~ /\((.*)\)/
-        end
-
-        def extract_precision(sql_type)
-          $2.to_i if sql_type =~ /^(numeric|decimal|number)\((\d+)(,\d+)?\)/i
-        end
-
-        def extract_scale(sql_type)
-          case sql_type
-            when /^(numeric|decimal|number)\((\d+)\)/i then 0
-            when /^(numeric|decimal|number)\((\d+)(,(\d+))\)/i then $4.to_i
-          end
-        end
-
-        def simplified_type(field_type)
-          case field_type
-            when /int/i
-              :integer
-            when /float|double/i
-              :float
-            when /decimal|numeric|number/i
-              extract_scale(field_type) == 0 ? :integer : :decimal
-            when /datetime/i
-              :datetime
-            when /timestamp/i
-              :timestamp
-            when /time/i
-              :time
-            when /date/i
-              :date
-            when /clob/i, /text/i
-              :text
-            when /blob/i, /binary/i
-              :binary
-            when /char/i, /string/i
-              :string
-            when /boolean/i
-              :boolean
-          end
-        end
-    end
-
     class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths) #:nodoc:
     end
 
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 5b9c48bafa..3ec7dd02a4 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -176,6 +176,13 @@ module ActiveRecord
       #    # Other column alterations here
       #  end
       #
+      # The +options+ hash can include the following keys:
+      # [<tt>:bulk</tt>]
+      #   Set this to true to make this a bulk alter query, such as
+      #   ALTER TABLE `users` ADD COLUMN age INT(11), ADD COLUMN birthdate DATETIME ...
+      #
+      #   Defaults to false.
+      #
       # ===== Examples
       # ====== Add a column
       #  change_table(:suppliers) do |t|
@@ -224,8 +231,14 @@ module ActiveRecord
       #
       # See also Table for details on
       # all of the various column transformation
-      def change_table(table_name)
-        yield Table.new(table_name, self)
+      def change_table(table_name, options = {})
+        if supports_bulk_alter? && options[:bulk]
+          recorder = ActiveRecord::Migration::CommandRecorder.new(self)
+          yield Table.new(table_name, recorder)
+          bulk_change_table(table_name, recorder.commands)
+        else
+          yield Table.new(table_name, self)
+        end
       end
 
       # Renames a table.
@@ -253,10 +266,7 @@ module ActiveRecord
       #  remove_column(:suppliers, :qualification)
       #  remove_columns(:suppliers, :qualification, :experience)
       def remove_column(table_name, *column_names)
-        raise ArgumentError.new("You must specify at least one column name.  Example: remove_column(:people, :first_name)") if column_names.empty?
-        column_names.flatten.each do |column_name|
-          execute "ALTER TABLE #{quote_table_name(table_name)} DROP #{quote_column_name(column_name)}"
-        end
+        columns_for_remove(table_name, *column_names).each {|column_name| execute "ALTER TABLE #{quote_table_name(table_name)} DROP #{column_name}" }
       end
       alias :remove_columns :remove_column
 
@@ -327,25 +337,8 @@ module ActiveRecord
       #
       # Note: SQLite doesn't support index length
       def add_index(table_name, column_name, options = {})
-        column_names = Array.wrap(column_name)
-        index_name   = index_name(table_name, :column => column_names)
-
-        if Hash === options # legacy support, since this param was a string
-          index_type = options[:unique] ? "UNIQUE" : ""
-          index_name = options[:name].to_s if options.key?(:name)
-        else
-          index_type = options
-        end
-
-        if index_name.length > index_name_length
-          raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' is too long; the limit is #{index_name_length} characters"
-        end
-        if index_name_exists?(table_name, index_name, false)
-          raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' already exists"
-        end
-        quoted_column_names = quoted_columns_for_index(column_names, options).join(", ")
-
-        execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} (#{quoted_column_names})"
+        index_name, index_type, index_columns = add_index_options(table_name, column_name, options)
+        execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} (#{index_columns})"
       end
 
       # Remove the given index from the table.
@@ -359,11 +352,7 @@ module ActiveRecord
       # Remove the index named by_branch_party in the accounts table.
       #   remove_index :accounts, :name => :by_branch_party
       def remove_index(table_name, options = {})
-        index_name = index_name(table_name, options)
-        unless index_name_exists?(table_name, index_name, true)
-          raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' does not exist"
-        end
-        remove_index!(table_name, index_name)
+        remove_index!(table_name, index_name_for_remove(table_name, options))
       end
 
       def remove_index!(table_name, index_name) #:nodoc:
@@ -469,7 +458,7 @@ module ActiveRecord
       end
 
       def type_to_sql(type, limit = nil, precision = nil, scale = nil) #:nodoc:
-        if native = native_database_types[type]
+        if native = native_database_types[type.to_sym]
           column_type_sql = (native.is_a?(Hash) ? native[:name] : native).dup
 
           if type == :decimal # ignore limit, use precision and scale
@@ -537,6 +526,45 @@ module ActiveRecord
           options.include?(:default) && !(options[:null] == false && options[:default].nil?)
         end
 
+        def add_index_options(table_name, column_name, options = {})
+          column_names = Array.wrap(column_name)
+          index_name   = index_name(table_name, :column => column_names)
+
+          if Hash === options # legacy support, since this param was a string
+            index_type = options[:unique] ? "UNIQUE" : ""
+            index_name = options[:name].to_s if options.key?(:name)
+          else
+            index_type = options
+          end
+
+          if index_name.length > index_name_length
+            raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' is too long; the limit is #{index_name_length} characters"
+          end
+          if index_name_exists?(table_name, index_name, false)
+            raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' already exists"
+          end
+          index_columns = quoted_columns_for_index(column_names, options).join(", ")
+
+          [index_name, index_type, index_columns]
+        end
+
+        def index_name_for_remove(table_name, options = {})
+          index_name = index_name(table_name, options)
+
+          unless index_name_exists?(table_name, index_name, true)
+            raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' does not exist"
+          end
+
+          index_name
+        end
+
+        def columns_for_remove(table_name, *column_names)
+          column_names = column_names.flatten
+
+          raise ArgumentError.new("You must specify at least one column name.  Example: remove_column(:people, :first_name)") if column_names.blank?
+          column_names.map {|column_name| quote_column_name(column_name) }
+        end
+
       private
       def table_definition
         TableDefinition.new(self)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 0282493219..0f44baa2fe 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -4,6 +4,7 @@ require 'bigdecimal/util'
 require 'active_support/core_ext/benchmark'
 
 # TODO: Autoload these files
+require 'active_record/connection_adapters/column'
 require 'active_record/connection_adapters/abstract/schema_definitions'
 require 'active_record/connection_adapters/abstract/schema_statements'
 require 'active_record/connection_adapters/abstract/database_statements'
@@ -77,8 +78,12 @@ module ActiveRecord
         false
       end
 
-      # Does this adapter support savepoints? PostgreSQL and MySQL do, SQLite
-      # does not.
+      def supports_bulk_alter?
+        false
+      end
+
+      # Does this adapter support savepoints? PostgreSQL and MySQL do,
+      # SQLite < 3.6.8 does not.
       def supports_savepoints?
         false
       end
@@ -204,11 +209,13 @@ module ActiveRecord
 
       protected
 
-        def log(sql, name = "SQL")
-          @instrumenter.instrument("sql.active_record",
-            :sql => sql, :name => name, :connection_id => object_id) do
-            yield
-          end
+        def log(sql, name = "SQL", binds = [])
+          @instrumenter.instrument(
+            "sql.active_record",
+            :sql           => sql,
+            :name          => name,
+            :connection_id => object_id,
+            :binds         => binds) { yield }
         rescue Exception => e
           message = "#{e.class.name}: #{e.message}: #{sql}"
           @logger.debug message if @logger
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
new file mode 100644
index 0000000000..4e3d8a096f
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -0,0 +1,268 @@
+module ActiveRecord
+  # :stopdoc:
+  module ConnectionAdapters
+    # An abstract definition of a column in a table.
+    class Column
+      TRUE_VALUES = [true, 1, '1', 't', 'T', 'true', 'TRUE'].to_set
+      FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE'].to_set
+
+      module Format
+        ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/
+        ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(\.\d+)?\z/
+      end
+
+      attr_reader :name, :default, :type, :limit, :null, :sql_type, :precision, :scale
+      attr_accessor :primary, :coder
+
+      alias :encoded? :coder
+
+      # Instantiates a new column in the table.
+      #
+      # +name+ is the column's name, such as <tt>supplier_id</tt> in <tt>supplier_id int(11)</tt>.
+      # +default+ is the type-casted default value, such as +new+ in <tt>sales_stage varchar(20) default 'new'</tt>.
+      # +sql_type+ is used to extract the column's length, if necessary. For example +60+ in
+      # <tt>company_name varchar(60)</tt>.
+      # It will be mapped to one of the standard Rails SQL types in the <tt>type</tt> attribute.
+      # +null+ determines if this column allows +NULL+ values.
+      def initialize(name, default, sql_type = nil, null = true)
+        @name      = name
+        @sql_type  = sql_type
+        @null      = null
+        @limit     = extract_limit(sql_type)
+        @precision = extract_precision(sql_type)
+        @scale     = extract_scale(sql_type)
+        @type      = simplified_type(sql_type)
+        @default   = extract_default(default)
+        @primary   = nil
+        @coder     = nil
+      end
+
+      # Returns +true+ if the column is either of type string or text.
+      def text?
+        type == :string || type == :text
+      end
+
+      # Returns +true+ if the column is either of type integer, float or decimal.
+      def number?
+        type == :integer || type == :float || type == :decimal
+      end
+
+      def has_default?
+        !default.nil?
+      end
+
+      # Returns the Ruby class that corresponds to the abstract data type.
+      def klass
+        case type
+        when :integer                     then Fixnum
+        when :float                       then Float
+        when :decimal                     then BigDecimal
+        when :datetime, :timestamp, :time then Time
+        when :date                        then Date
+        when :text, :string, :binary      then String
+        when :boolean                     then Object
+        end
+      end
+
+      # Casts value (which is a String) to an appropriate instance.
+      def type_cast(value)
+        return nil if value.nil?
+        return coder.load(value) if encoded?
+
+        klass = self.class
+
+        case type
+        when :string, :text        then value
+        when :integer              then value.to_i rescue value ? 1 : 0
+        when :float                then value.to_f
+        when :decimal              then klass.value_to_decimal(value)
+        when :datetime, :timestamp then klass.string_to_time(value)
+        when :time                 then klass.string_to_dummy_time(value)
+        when :date                 then klass.string_to_date(value)
+        when :binary               then klass.binary_to_string(value)
+        when :boolean              then klass.value_to_boolean(value)
+        else value
+        end
+      end
+
+      def type_cast_code(var_name)
+        klass = self.class.name
+
+        case type
+        when :string, :text        then var_name
+        when :integer              then "(#{var_name}.to_i rescue #{var_name} ? 1 : 0)"
+        when :float                then "#{var_name}.to_f"
+        when :decimal              then "#{klass}.value_to_decimal(#{var_name})"
+        when :datetime, :timestamp then "#{klass}.string_to_time(#{var_name})"
+        when :time                 then "#{klass}.string_to_dummy_time(#{var_name})"
+        when :date                 then "#{klass}.string_to_date(#{var_name})"
+        when :binary               then "#{klass}.binary_to_string(#{var_name})"
+        when :boolean              then "#{klass}.value_to_boolean(#{var_name})"
+        else var_name
+        end
+      end
+
+      # Returns the human name of the column name.
+      #
+      # ===== Examples
+      #  Column.new('sales_stage', ...).human_name # => 'Sales stage'
+      def human_name
+        Base.human_attribute_name(@name)
+      end
+
+      def extract_default(default)
+        type_cast(default)
+      end
+
+      # Used to convert from Strings to BLOBs
+      def string_to_binary(value)
+        self.class.string_to_binary(value)
+      end
+
+      class << self
+        # Used to convert from Strings to BLOBs
+        def string_to_binary(value)
+          value
+        end
+
+        # Used to convert from BLOBs to Strings
+        def binary_to_string(value)
+          value
+        end
+
+        def string_to_date(string)
+          return string unless string.is_a?(String)
+          return nil if string.empty?
+
+          fast_string_to_date(string) || fallback_string_to_date(string)
+        end
+
+        def string_to_time(string)
+          return string unless string.is_a?(String)
+          return nil if string.empty?
+
+          fast_string_to_time(string) || fallback_string_to_time(string)
+        end
+
+        def string_to_dummy_time(string)
+          return string unless string.is_a?(String)
+          return nil if string.empty?
+
+          string_to_time "2000-01-01 #{string}"
+        end
+
+        # convert something to a boolean
+        def value_to_boolean(value)
+          if value.is_a?(String) && value.blank?
+            nil
+          else
+            TRUE_VALUES.include?(value)
+          end
+        end
+
+        # convert something to a BigDecimal
+        def value_to_decimal(value)
+          # Using .class is faster than .is_a? and
+          # subclasses of BigDecimal will be handled
+          # in the else clause
+          if value.class == BigDecimal
+            value
+          elsif value.respond_to?(:to_d)
+            value.to_d
+          else
+            value.to_s.to_d
+          end
+        end
+
+        protected
+          # '0.123456' -> 123456
+          # '1.123456' -> 123456
+          def microseconds(time)
+            ((time[:sec_fraction].to_f % 1) * 1_000_000).to_i
+          end
+
+          def new_date(year, mon, mday)
+            if year && year != 0
+              Date.new(year, mon, mday) rescue nil
+            end
+          end
+
+          def new_time(year, mon, mday, hour, min, sec, microsec)
+            # Treat 0000-00-00 00:00:00 as nil.
+            return nil if year.nil? || year == 0
+
+            Time.time_with_datetime_fallback(Base.default_timezone, year, mon, mday, hour, min, sec, microsec) rescue nil
+          end
+
+          def fast_string_to_date(string)
+            if string =~ Format::ISO_DATE
+              new_date $1.to_i, $2.to_i, $3.to_i
+            end
+          end
+
+          # Doesn't handle time zones.
+          def fast_string_to_time(string)
+            if string =~ Format::ISO_DATETIME
+              microsec = ($7.to_f * 1_000_000).to_i
+              new_time $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, microsec
+            end
+          end
+
+          def fallback_string_to_date(string)
+            new_date(*::Date._parse(string, false).values_at(:year, :mon, :mday))
+          end
+
+          def fallback_string_to_time(string)
+            time_hash = Date._parse(string)
+            time_hash[:sec_fraction] = microseconds(time_hash)
+
+            new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction))
+          end
+      end
+
+      private
+        def extract_limit(sql_type)
+          $1.to_i if sql_type =~ /\((.*)\)/
+        end
+
+        def extract_precision(sql_type)
+          $2.to_i if sql_type =~ /^(numeric|decimal|number)\((\d+)(,\d+)?\)/i
+        end
+
+        def extract_scale(sql_type)
+          case sql_type
+            when /^(numeric|decimal|number)\((\d+)\)/i then 0
+            when /^(numeric|decimal|number)\((\d+)(,(\d+))\)/i then $4.to_i
+          end
+        end
+
+        def simplified_type(field_type)
+          case field_type
+          when /int/i
+            :integer
+          when /float|double/i
+            :float
+          when /decimal|numeric|number/i
+            extract_scale(field_type) == 0 ? :integer : :decimal
+          when /datetime/i
+            :datetime
+          when /timestamp/i
+            :timestamp
+          when /time/i
+            :time
+          when /date/i
+            :date
+          when /clob/i, /text/i
+            :text
+          when /blob/i, /binary/i
+            :binary
+          when /char/i, /string/i
+            :string
+          when /boolean/i
+            :boolean
+          end
+        end
+    end
+  end
+  # :startdoc:
+end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
new file mode 100644
index 0000000000..7bad511c64
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
@@ -0,0 +1,610 @@
+# encoding: utf-8
+
+require 'mysql2'
+
+module ActiveRecord
+  class Base
+    def self.mysql2_connection(config)
+      config[:username] = 'root' if config[:username].nil?
+
+      if Mysql2::Client.const_defined? :FOUND_ROWS
+        config[:flags] = Mysql2::Client::FOUND_ROWS
+      end
+
+      client = Mysql2::Client.new(config.symbolize_keys)
+      options = [config[:host], config[:username], config[:password], config[:database], config[:port], config[:socket], 0]
+      ConnectionAdapters::Mysql2Adapter.new(client, logger, options, config)
+    end
+  end
+
+  module ConnectionAdapters
+    class Mysql2IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths) #:nodoc:
+    end
+
+    class Mysql2Column < Column
+      BOOL = "tinyint(1)"
+      def extract_default(default)
+        if sql_type =~ /blob/i || type == :text
+          if default.blank?
+            return null ? nil : ''
+          else
+            raise ArgumentError, "#{type} columns cannot have a default value: #{default.inspect}"
+          end
+        elsif missing_default_forged_as_empty_string?(default)
+          nil
+        else
+          super
+        end
+      end
+
+      def has_default?
+        return false if sql_type =~ /blob/i || type == :text #mysql forbids defaults on blob and text columns
+        super
+      end
+
+      private
+        def simplified_type(field_type)
+          return :boolean if Mysql2Adapter.emulate_booleans && field_type.downcase.index(BOOL)
+
+          case field_type
+          when /enum/i, /set/i then :string
+          when /year/i         then :integer
+          when /bit/i          then :binary
+          else
+            super
+          end
+        end
+
+        def extract_limit(sql_type)
+          case sql_type
+          when /blob|text/i
+            case sql_type
+            when /tiny/i
+              255
+            when /medium/i
+              16777215
+            when /long/i
+              2147483647 # mysql only allows 2^31-1, not 2^32-1, somewhat inconsistently with the tiny/medium/normal cases
+            else
+              super # we could return 65535 here, but we leave it undecorated by default
+            end
+          when /^bigint/i;    8
+          when /^int/i;       4
+          when /^mediumint/i; 3
+          when /^smallint/i;  2
+          when /^tinyint/i;   1
+          else
+            super
+          end
+        end
+
+        # MySQL misreports NOT NULL column default when none is given.
+        # We can't detect this for columns which may have a legitimate ''
+        # default (string) but we can for others (integer, datetime, boolean,
+        # and the rest).
+        #
+        # Test whether the column has default '', is not null, and is not
+        # a type allowing default ''.
+        def missing_default_forged_as_empty_string?(default)
+          type != :string && !null && default == ''
+        end
+    end
+
+    class Mysql2Adapter < AbstractAdapter
+      cattr_accessor :emulate_booleans
+      self.emulate_booleans = true
+
+      ADAPTER_NAME = 'Mysql2'
+      PRIMARY = "PRIMARY"
+
+      LOST_CONNECTION_ERROR_MESSAGES = [
+        "Server shutdown in progress",
+        "Broken pipe",
+        "Lost connection to MySQL server during query",
+        "MySQL server has gone away" ]
+
+      QUOTED_TRUE, QUOTED_FALSE = '1', '0'
+
+      NATIVE_DATABASE_TYPES = {
+        :primary_key => "int(11) DEFAULT NULL auto_increment PRIMARY KEY",
+        :string      => { :name => "varchar", :limit => 255 },
+        :text        => { :name => "text" },
+        :integer     => { :name => "int", :limit => 4 },
+        :float       => { :name => "float" },
+        :decimal     => { :name => "decimal" },
+        :datetime    => { :name => "datetime" },
+        :timestamp   => { :name => "datetime" },
+        :time        => { :name => "time" },
+        :date        => { :name => "date" },
+        :binary      => { :name => "blob" },
+        :boolean     => { :name => "tinyint", :limit => 1 }
+      }
+
+      def initialize(connection, logger, connection_options, config)
+        super(connection, logger)
+        @connection_options, @config = connection_options, config
+        @quoted_column_names, @quoted_table_names = {}, {}
+        configure_connection
+      end
+
+      def adapter_name
+        ADAPTER_NAME
+      end
+
+      def supports_migrations?
+        true
+      end
+
+      def supports_primary_key?
+        true
+      end
+
+      def supports_savepoints?
+        true
+      end
+
+      def native_database_types
+        NATIVE_DATABASE_TYPES
+      end
+
+      # QUOTING ==================================================
+
+      def quote(value, column = nil)
+        if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary)
+          s = column.class.string_to_binary(value).unpack("H*")[0]
+          "x'#{s}'"
+        elsif value.kind_of?(BigDecimal)
+          value.to_s("F")
+        else
+          super
+        end
+      end
+
+      def quote_column_name(name) #:nodoc:
+        @quoted_column_names[name] ||= "`#{name}`"
+      end
+
+      def quote_table_name(name) #:nodoc:
+        @quoted_table_names[name] ||= quote_column_name(name).gsub('.', '`.`')
+      end
+
+      def quote_string(string)
+        @connection.escape(string)
+      end
+
+      def quoted_true
+        QUOTED_TRUE
+      end
+
+      def quoted_false
+        QUOTED_FALSE
+      end
+
+      # REFERENTIAL INTEGRITY ====================================
+
+      def disable_referential_integrity(&block) #:nodoc:
+        old = select_value("SELECT @@FOREIGN_KEY_CHECKS")
+
+        begin
+          update("SET FOREIGN_KEY_CHECKS = 0")
+          yield
+        ensure
+          update("SET FOREIGN_KEY_CHECKS = #{old}")
+        end
+      end
+
+      # CONNECTION MANAGEMENT ====================================
+
+      def active?
+        return false unless @connection
+        @connection.ping
+      end
+
+      def reconnect!
+        disconnect!
+        connect
+      end
+
+      # this is set to true in 2.3, but we don't want it to be
+      def requires_reloading?
+        false
+      end
+
+      def disconnect!
+        unless @connection.nil?
+          @connection.close
+          @connection = nil
+        end
+      end
+
+      def reset!
+        disconnect!
+        connect
+      end
+
+      # DATABASE STATEMENTS ======================================
+
+      # FIXME: re-enable the following once a "better" query_cache solution is in core
+      #
+      # The overrides below perform much better than the originals in AbstractAdapter
+      # because we're able to take advantage of mysql2's lazy-loading capabilities
+      #
+      # # Returns a record hash with the column names as keys and column values
+      # # as values.
+      # def select_one(sql, name = nil)
+      #   result = execute(sql, name)
+      #   result.each(:as => :hash) do |r|
+      #     return r
+      #   end
+      # end
+      #
+      # # Returns a single value from a record
+      # def select_value(sql, name = nil)
+      #   result = execute(sql, name)
+      #   if first = result.first
+      #     first.first
+      #   end
+      # end
+      #
+      # # Returns an array of the values of the first column in a select:
+      # #   select_values("SELECT id FROM companies LIMIT 3") => [1,2,3]
+      # def select_values(sql, name = nil)
+      #   execute(sql, name).map { |row| row.first }
+      # end
+
+      # Returns an array of arrays containing the field values.
+      # Order is the same as that returned by +columns+.
+      def select_rows(sql, name = nil)
+        execute(sql, name).to_a
+      end
+
+      # Executes the SQL statement in the context of this connection.
+      def execute(sql, name = nil)
+        # make sure we carry over any changes to ActiveRecord::Base.default_timezone that have been
+        # made since we established the connection
+        @connection.query_options[:database_timezone] = ActiveRecord::Base.default_timezone
+        if name == :skip_logging
+          @connection.query(sql)
+        else
+          log(sql, name) { @connection.query(sql) }
+        end
+      rescue ActiveRecord::StatementInvalid => exception
+        if exception.message.split(":").first =~ /Packets out of order/
+          raise ActiveRecord::StatementInvalid, "'Packets out of order' error was received from the database. Please update your mysql bindings (gem install mysql) and read http://dev.mysql.com/doc/mysql/en/password-hashing.html for more information.  If you're on Windows, use the Instant Rails installer to get the updated mysql bindings."
+        else
+          raise
+        end
+      end
+
+      def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
+        super
+        id_value || @connection.last_id
+      end
+      alias :create :insert_sql
+
+      def update_sql(sql, name = nil)
+        super
+        @connection.affected_rows
+      end
+
+      def begin_db_transaction
+        execute "BEGIN"
+      rescue Exception
+        # Transactions aren't supported
+      end
+
+      def commit_db_transaction
+        execute "COMMIT"
+      rescue Exception
+        # Transactions aren't supported
+      end
+
+      def rollback_db_transaction
+        execute "ROLLBACK"
+      rescue Exception
+        # Transactions aren't supported
+      end
+
+      def create_savepoint
+        execute("SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def rollback_to_savepoint
+        execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def release_savepoint
+        execute("RELEASE SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def add_limit_offset!(sql, options)
+        limit, offset = options[:limit], options[:offset]
+        if limit && offset
+          sql << " LIMIT #{offset.to_i}, #{sanitize_limit(limit)}"
+        elsif limit
+          sql << " LIMIT #{sanitize_limit(limit)}"
+        elsif offset
+          sql << " OFFSET #{offset.to_i}"
+        end
+        sql
+      end
+      deprecate :add_limit_offset!
+
+      # SCHEMA STATEMENTS ========================================
+
+      def structure_dump
+        if supports_views?
+          sql = "SHOW FULL TABLES WHERE Table_type = 'BASE TABLE'"
+        else
+          sql = "SHOW TABLES"
+        end
+
+        select_all(sql).inject("") do |structure, table|
+          table.delete('Table_type')
+          structure += select_one("SHOW CREATE TABLE #{quote_table_name(table.to_a.first.last)}")["Create Table"] + ";\n\n"
+        end
+      end
+
+      def recreate_database(name, options = {})
+        drop_database(name)
+        create_database(name, options)
+      end
+
+      # Create a new MySQL database with optional <tt>:charset</tt> and <tt>:collation</tt>.
+      # Charset defaults to utf8.
+      #
+      # Example:
+      #   create_database 'charset_test', :charset => 'latin1', :collation => 'latin1_bin'
+      #   create_database 'matt_development'
+      #   create_database 'matt_development', :charset => :big5
+      def create_database(name, options = {})
+        if options[:collation]
+          execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}` COLLATE `#{options[:collation]}`"
+        else
+          execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}`"
+        end
+      end
+
+      def drop_database(name) #:nodoc:
+        execute "DROP DATABASE IF EXISTS `#{name}`"
+      end
+
+      def current_database
+        select_value 'SELECT DATABASE() as db'
+      end
+
+      # Returns the database character set.
+      def charset
+        show_variable 'character_set_database'
+      end
+
+      # Returns the database collation strategy.
+      def collation
+        show_variable 'collation_database'
+      end
+
+      def tables(name = nil)
+        tables = []
+        execute("SHOW TABLES", name).each do |field|
+          tables << field.first
+        end
+        tables
+      end
+
+      def drop_table(table_name, options = {})
+        super(table_name, options)
+      end
+
+      def indexes(table_name, name = nil)
+        indexes = []
+        current_index = nil
+        result = execute("SHOW KEYS FROM #{quote_table_name(table_name)}", name)
+        result.each(:symbolize_keys => true, :as => :hash) do |row|
+          if current_index != row[:Key_name]
+            next if row[:Key_name] == PRIMARY # skip the primary key
+            current_index = row[:Key_name]
+            indexes << Mysql2IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique] == 0, [], [])
+          end
+
+          indexes.last.columns << row[:Column_name]
+          indexes.last.lengths << row[:Sub_part]
+        end
+        indexes
+      end
+
+      def columns(table_name, name = nil)
+        sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
+        columns = []
+        result = execute(sql)
+        result.each(:symbolize_keys => true, :as => :hash) { |field|
+          columns << Mysql2Column.new(field[:Field], field[:Default], field[:Type], field[:Null] == "YES")
+        }
+        columns
+      end
+
+      def create_table(table_name, options = {})
+        super(table_name, options.reverse_merge(:options => "ENGINE=InnoDB"))
+      end
+
+      def rename_table(table_name, new_name)
+        execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
+      end
+
+      def add_column(table_name, column_name, type, options = {})
+        add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
+        add_column_options!(add_column_sql, options)
+        add_column_position!(add_column_sql, options)
+        execute(add_column_sql)
+      end
+
+      def change_column_default(table_name, column_name, default)
+        column = column_for(table_name, column_name)
+        change_column table_name, column_name, column.sql_type, :default => default
+      end
+
+      def change_column_null(table_name, column_name, null, default = nil)
+        column = column_for(table_name, column_name)
+
+        unless null || default.nil?
+          execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
+        end
+
+        change_column table_name, column_name, column.sql_type, :null => null
+      end
+
+      def change_column(table_name, column_name, type, options = {})
+        column = column_for(table_name, column_name)
+
+        unless options_include_default?(options)
+          options[:default] = column.default
+        end
+
+        unless options.has_key?(:null)
+          options[:null] = column.null
+        end
+
+        change_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
+        add_column_options!(change_column_sql, options)
+        add_column_position!(change_column_sql, options)
+        execute(change_column_sql)
+      end
+
+      def rename_column(table_name, column_name, new_column_name)
+        options = {}
+        if column = columns(table_name).find { |c| c.name == column_name.to_s }
+          options[:default] = column.default
+          options[:null] = column.null
+        else
+          raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
+        end
+        current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]
+        rename_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
+        add_column_options!(rename_column_sql, options)
+        execute(rename_column_sql)
+      end
+
+      # Maps logical Rails types to MySQL-specific data types.
+      def type_to_sql(type, limit = nil, precision = nil, scale = nil)
+        return super unless type.to_s == 'integer'
+
+        case limit
+        when 1; 'tinyint'
+        when 2; 'smallint'
+        when 3; 'mediumint'
+        when nil, 4, 11; 'int(11)'  # compatibility with MySQL default
+        when 5..8; 'bigint'
+        else raise(ActiveRecordError, "No integer type has byte size #{limit}")
+        end
+      end
+
+      def add_column_position!(sql, options)
+        if options[:first]
+          sql << " FIRST"
+        elsif options[:after]
+          sql << " AFTER #{quote_column_name(options[:after])}"
+        end
+      end
+
+      def show_variable(name)
+        variables = select_all("SHOW VARIABLES LIKE '#{name}'")
+        variables.first['Value'] unless variables.empty?
+      end
+
+      def pk_and_sequence_for(table)
+        keys = []
+        result = execute("describe #{quote_table_name(table)}")
+        result.each(:symbolize_keys => true, :as => :hash) do |row|
+          keys << row[:Field] if row[:Key] == "PRI"
+        end
+        keys.length == 1 ? [keys.first, nil] : nil
+      end
+
+      # Returns just a table's primary key
+      def primary_key(table)
+        pk_and_sequence = pk_and_sequence_for(table)
+        pk_and_sequence && pk_and_sequence.first
+      end
+
+      def case_sensitive_equality_operator
+        "= BINARY"
+      end
+
+      def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
+        where_sql
+      end
+
+      protected
+        def quoted_columns_for_index(column_names, options = {})
+          length = options[:length] if options.is_a?(Hash)
+
+          quoted_column_names = case length
+          when Hash
+            column_names.map {|name| length[name] ? "#{quote_column_name(name)}(#{length[name]})" : quote_column_name(name) }
+          when Fixnum
+            column_names.map {|name| "#{quote_column_name(name)}(#{length})"}
+          else
+            column_names.map {|name| quote_column_name(name) }
+          end
+        end
+
+        def translate_exception(exception, message)
+          return super unless exception.respond_to?(:error_number)
+
+          case exception.error_number
+          when 1062
+            RecordNotUnique.new(message, exception)
+          when 1452
+            InvalidForeignKey.new(message, exception)
+          else
+            super
+          end
+        end
+
+      private
+        def connect
+          @connection = Mysql2::Client.new(@config)
+          configure_connection
+        end
+
+        def configure_connection
+          @connection.query_options.merge!(:as => :array)
+
+          # By default, MySQL 'where id is null' selects the last inserted id.
+          # Turn this off. http://dev.rubyonrails.org/ticket/6778
+          variable_assignments = ['SQL_AUTO_IS_NULL=0']
+          encoding = @config[:encoding]
+
+          # make sure we set the encoding
+          variable_assignments << "NAMES '#{encoding}'" if encoding
+
+          # increase timeout so mysql server doesn't disconnect us
+          wait_timeout = @config[:wait_timeout]
+          wait_timeout = 2592000 unless wait_timeout.is_a?(Fixnum)
+          variable_assignments << "@@wait_timeout = #{wait_timeout}"
+
+          execute("SET #{variable_assignments.join(', ')}", :skip_logging)
+        end
+
+        # Returns an array of record hashes with the column names as keys and
+        # column values as values.
+        def select(sql, name = nil)
+          execute(sql, name).each(:as => :hash)
+        end
+
+        def supports_views?
+          version[0] >= 5
+        end
+
+        def version
+          @version ||= @connection.info[:version].scan(/^(\d+)\.(\d+)\.(\d+)/).flatten.map { |v| v.to_i }
+        end
+
+        def column_for(table_name, column_name)
+          unless column = columns(table_name).find { |c| c.name == column_name.to_s }
+            raise "No such column: #{table_name}.#{column_name}"
+          end
+          column
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index ce2352486b..368c5b2023 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -203,6 +203,10 @@ module ActiveRecord
         ADAPTER_NAME
       end
 
+      def supports_bulk_alter? #:nodoc:
+        true
+      end
+
       # Returns +true+ when the connection adapter supports prepared statement
       # caching, otherwise returns +false+
       def supports_statement_cache?
@@ -327,7 +331,7 @@ module ActiveRecord
       end
 
       def exec_query(sql, name = 'SQL', binds = [])
-        log(sql, name) do
+        log(sql, name, binds) do
           result = nil
 
           cache = {}
@@ -364,9 +368,14 @@ module ActiveRecord
         # statement API.  For those queries, we need to use this method. :'(
         log(sql, name) do
           result = @connection.query(sql)
-          cols = result.fetch_fields.map { |field| field.name }
-          rows = result.to_a
-          result.free
+          cols = []
+          rows = []
+
+          if result
+            cols = result.fetch_fields.map { |field| field.name }
+            rows = result.to_a
+            result.free
+          end
           ActiveRecord::Result.new(cols, rows)
         end
       end
@@ -400,7 +409,7 @@ module ActiveRecord
 
       def begin_db_transaction #:nodoc:
         exec_without_stmt "BEGIN"
-      rescue Exception
+      rescue Mysql::Error
         # Transactions aren't supported
       end
 
@@ -439,6 +448,7 @@ module ActiveRecord
         end
         sql
       end
+      deprecate :add_limit_offset!
 
       # SCHEMA STATEMENTS ========================================
 
@@ -527,7 +537,7 @@ module ActiveRecord
       def columns(table_name, name = nil)#:nodoc:
         sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
         columns = []
-        result = execute(sql, :skip_logging)
+        result = execute(sql)
         result.each { |field| columns << MysqlColumn.new(field[0], field[4], field[1], field[2] == "YES") }
         result.free
         columns
@@ -541,11 +551,23 @@ module ActiveRecord
         execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
       end
 
+      def bulk_change_table(table_name, operations) #:nodoc:
+        sqls = operations.map do |command, args|
+          table, arguments = args.shift, args
+          method = :"#{command}_sql"
+
+          if respond_to?(method)
+            send(method, table, *arguments)
+          else
+            raise "Unknown method called : #{method}(#{arguments.inspect})"
+          end
+        end.flatten.join(", ")
+
+        execute("ALTER TABLE #{quote_table_name(table_name)} #{sqls}")
+      end
+
       def add_column(table_name, column_name, type, options = {})
-        add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
-        add_column_options!(add_column_sql, options)
-        add_column_position!(add_column_sql, options)
-        execute(add_column_sql)
+        execute("ALTER TABLE #{quote_table_name(table_name)} #{add_column_sql(table_name, column_name, type, options)}")
       end
 
       def change_column_default(table_name, column_name, default) #:nodoc:
@@ -564,34 +586,11 @@ module ActiveRecord
       end
 
       def change_column(table_name, column_name, type, options = {}) #:nodoc:
-        column = column_for(table_name, column_name)
-
-        unless options_include_default?(options)
-          options[:default] = column.default
-        end
-
-        unless options.has_key?(:null)
-          options[:null] = column.null
-        end
-
-        change_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
-        add_column_options!(change_column_sql, options)
-        add_column_position!(change_column_sql, options)
-        execute(change_column_sql)
+        execute("ALTER TABLE #{quote_table_name(table_name)} #{change_column_sql(table_name, column_name, type, options)}")
       end
 
       def rename_column(table_name, column_name, new_column_name) #:nodoc:
-        options = {}
-        if column = columns(table_name).find { |c| c.name == column_name.to_s }
-          options[:default] = column.default
-          options[:null] = column.null
-        else
-          raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
-        end
-        current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]
-        rename_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
-        add_column_options!(rename_column_sql, options)
-        execute(rename_column_sql)
+        execute("ALTER TABLE #{quote_table_name(table_name)} #{rename_column_sql(table_name, column_name, new_column_name)}")
       end
 
       # Maps logical Rails types to MySQL-specific data types.
@@ -674,6 +673,69 @@ module ActiveRecord
           end
         end
 
+        def add_column_sql(table_name, column_name, type, options = {})
+          add_column_sql = "ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
+          add_column_options!(add_column_sql, options)
+          add_column_position!(add_column_sql, options)
+          add_column_sql
+        end
+
+        def remove_column_sql(table_name, *column_names)
+          columns_for_remove(table_name, *column_names).map {|column_name| "DROP #{column_name}" }
+        end
+        alias :remove_columns_sql :remove_column
+
+        def change_column_sql(table_name, column_name, type, options = {})
+          column = column_for(table_name, column_name)
+
+          unless options_include_default?(options)
+            options[:default] = column.default
+          end
+
+          unless options.has_key?(:null)
+            options[:null] = column.null
+          end
+
+          change_column_sql = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
+          add_column_options!(change_column_sql, options)
+          add_column_position!(change_column_sql, options)
+          change_column_sql
+        end
+
+        def rename_column_sql(table_name, column_name, new_column_name)
+          options = {}
+
+          if column = columns(table_name).find { |c| c.name == column_name.to_s }
+            options[:default] = column.default
+            options[:null] = column.null
+          else
+            raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
+          end
+
+          current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]
+          rename_column_sql = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
+          add_column_options!(rename_column_sql, options)
+          rename_column_sql
+        end
+
+        def add_index_sql(table_name, column_name, options = {})
+          index_name, index_type, index_columns = add_index_options(table_name, column_name, options)
+          "ADD #{index_type} INDEX #{index_name} (#{index_columns})"
+        end
+
+        def remove_index_sql(table_name, options = {})
+          index_name = index_name_for_remove(table_name, options)
+          "DROP INDEX #{index_name}"
+        end
+
+        def add_timestamps_sql(table_name)
+          [add_column_sql(table_name, :created_at, :datetime), add_column_sql(table_name, :updated_at, :datetime)]
+        end
+
+        def remove_timestamps_sql(table_name)
+          [remove_column_sql(table_name, :updated_at), remove_column_sql(table_name, :created_at)]
+        end
+
       private
         def connect
           encoding = @config[:encoding]
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index a4b1aa7154..20be4a22ea 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -532,7 +532,7 @@ module ActiveRecord
       def exec_query(sql, name = 'SQL', binds = [])
         return exec_no_cache(sql, name) if binds.empty?
 
-        log(sql, name) do
+        log(sql, name, binds) do
           unless @statements.key? sql
             nextkey = "a#{@statements.length + 1}"
             @connection.prepare nextkey, sql
@@ -786,7 +786,7 @@ module ActiveRecord
       def pk_and_sequence_for(table) #:nodoc:
         # First try looking for a sequence with a dependency on the
         # given table's primary key.
-        result = query(<<-end_sql, 'PK and serial sequence')[0]
+        result = exec_query(<<-end_sql, 'PK and serial sequence').rows.first
           SELECT attr.attname, seq.relname
           FROM pg_class      seq,
                pg_attribute  attr,
@@ -1071,7 +1071,7 @@ module ActiveRecord
         #  - format_type includes the column size constraint, e.g. varchar(50)
         #  - ::regclass is a function that gives the id for a table name
         def column_definitions(table_name) #:nodoc:
-          query <<-end_sql
+          exec_query(<<-end_sql).rows
             SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
               FROM pg_attribute a LEFT JOIN pg_attrdef d
                 ON a.attrelid = d.adrelid AND a.attnum = d.adnum
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index d76fc4103e..9ee6b88ab6 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -62,6 +62,10 @@ module ActiveRecord
         sqlite_version >= '2.0.0'
       end
 
+      def supports_savepoints?
+        sqlite_version >= '3.6.8'
+      end
+
       # Returns +true+ when the connection adapter supports prepared statement
       # caching, otherwise returns +false+
       def supports_statement_cache?
@@ -144,12 +148,15 @@ module ActiveRecord
       # DATABASE STATEMENTS ======================================
 
       def exec_query(sql, name = nil, binds = [])
-        log(sql, name) do
+        log(sql, name, binds) do
 
           # Don't cache statements without bind values
           if binds.empty?
-            stmt = @connection.prepare(sql)
-            cols = stmt.columns
+            stmt    = @connection.prepare(sql)
+            cols    = stmt.columns
+            records = stmt.to_a
+            stmt.close
+            stmt = records
           else
             cache = @statements[sql] ||= {
               :stmt => @connection.prepare(sql)
@@ -189,6 +196,18 @@ module ActiveRecord
         exec_query(sql, name).rows
       end
 
+      def create_savepoint
+        execute("SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def rollback_to_savepoint
+        execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def release_savepoint
+        execute("RELEASE SAVEPOINT #{current_savepoint_name}")
+      end
+
       def begin_db_transaction #:nodoc:
         @connection.transaction
       end
@@ -217,6 +236,15 @@ module ActiveRecord
 
       def columns(table_name, name = nil) #:nodoc:
         table_structure(table_name).map do |field|
+          case field["dflt_value"]
+          when /^null$/i
+            field["dflt_value"] = nil
+          when /^'(.*)'$/
+            field["dflt_value"] = $1.gsub(/''/, "'")
+          when /^"(.*)"$/
+            field["dflt_value"] = $1.gsub(/""/, '"')
+          end
+
           SQLiteColumn.new(field['name'], field['dflt_value'], field['type'], field['notnull'].to_i == 0)
         end
       end
@@ -314,16 +342,11 @@ module ActiveRecord
 
       protected
         def select(sql, name = nil, binds = []) #:nodoc:
-          result = exec_query(sql, name, binds)
-          columns = result.columns.map { |column|
-            column.sub(/^"?\w+"?\./, '')
-          }
-
-          result.rows.map { |row| Hash[columns.zip(row)] }
+          exec_query(sql, name, binds).to_a
         end
 
         def table_structure(table_name)
-          structure = @connection.table_info(quote_table_name(table_name))
+          structure = exec_query("PRAGMA table_info(#{quote_table_name(table_name)})").to_hash
           raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
           structure
         end
diff --git a/activerecord/lib/active_record/fixtures.rb b/activerecord/lib/active_record/fixtures.rb
index b46310f8e0..f065ef7753 100644
--- a/activerecord/lib/active_record/fixtures.rb
+++ b/activerecord/lib/active_record/fixtures.rb
@@ -1,4 +1,10 @@
 require 'erb'
+
+begin
+  require 'psych'
+rescue LoadError
+end
+
 require 'yaml'
 require 'csv'
 require 'zlib'
@@ -6,15 +12,7 @@ require 'active_support/dependencies'
 require 'active_support/core_ext/array/wrap'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/logger'
-
-if RUBY_VERSION < '1.9'
-  module YAML #:nodoc:
-    class Omap #:nodoc:
-      def keys;   map { |k, v| k } end
-      def values; map { |k, v| v } end
-    end
-  end
-end
+require 'active_support/ordered_hash'
 
 if defined? ActiveRecord
   class FixtureClassNotFound < ActiveRecord::ActiveRecordError #:nodoc:
@@ -446,20 +444,24 @@ class FixturesFileNotFound < StandardError; end
 #
 # Any fixture labeled "DEFAULTS" is safely ignored.
 
-class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
+class Fixtures
   MAX_ID = 2 ** 30 - 1
   DEFAULT_FILTER_RE = /\.ya?ml$/
 
-  @@all_cached_fixtures = {}
+  @@all_cached_fixtures = Hash.new { |h,k| h[k] = {} }
 
-  def self.reset_cache(connection = nil)
-    connection ||= ActiveRecord::Base.connection
-    @@all_cached_fixtures[connection.object_id] = {}
+  def self.find_table_name(table_name) # :nodoc:
+    ActiveRecord::Base.pluralize_table_names ?
+      table_name.to_s.singularize.camelize :
+      table_name.to_s.camelize
+  end
+
+  def self.reset_cache
+    @@all_cached_fixtures.clear
   end
 
   def self.cache_for_connection(connection)
-    @@all_cached_fixtures[connection.object_id] ||= {}
-    @@all_cached_fixtures[connection.object_id]
+    @@all_cached_fixtures[connection]
   end
 
   def self.fixture_is_cached?(connection, table_name)
@@ -468,11 +470,10 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
 
   def self.cached_fixtures(connection, keys_to_fetch = nil)
     if keys_to_fetch
-      fixtures = cache_for_connection(connection).values_at(*keys_to_fetch)
+      cache_for_connection(connection).values_at(*keys_to_fetch)
     else
-      fixtures = cache_for_connection(connection).values
+      cache_for_connection(connection).values
     end
-    fixtures.size > 1 ? fixtures : fixtures.first
   end
 
   def self.cache_fixtures(connection, fixtures_map)
@@ -482,13 +483,11 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
   def self.instantiate_fixtures(object, table_name, fixtures, load_instances = true)
     object.instance_variable_set "@#{table_name.to_s.gsub('.','_')}", fixtures
     if load_instances
-      ActiveRecord::Base.silence do
-        fixtures.each do |name, fixture|
-          begin
-            object.instance_variable_set "@#{name}", fixture.find
-          rescue FixtureClassNotFound
-            nil
-          end
+      fixtures.each do |name, fixture|
+        begin
+          object.instance_variable_set "@#{name}", fixture.find
+        rescue FixtureClassNotFound
+          nil
         end
       end
     end
@@ -505,36 +504,56 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
 
   def self.create_fixtures(fixtures_directory, table_names, class_names = {})
     table_names = [table_names].flatten.map { |n| n.to_s }
-    table_names.each { |n| class_names[n.tr('/', '_').to_sym] = n.classify if n.include?('/') }
-    connection  = block_given? ? yield : ActiveRecord::Base.connection
+    table_names.each { |n|
+      class_names[n.tr('/', '_').to_sym] = n.classify if n.include?('/')
+    }
 
-    table_names_to_fetch = table_names.reject { |table_name| fixture_is_cached?(connection, table_name) }
+    # FIXME: Apparently JK uses this.
+    connection = block_given? ? yield : ActiveRecord::Base.connection
 
-    unless table_names_to_fetch.empty?
-      ActiveRecord::Base.silence do
-        connection.disable_referential_integrity do
-          fixtures_map = {}
+    files_to_read = table_names.reject { |table_name| fixture_is_cached?(connection, table_name) }
 
-          fixtures = table_names_to_fetch.map do |table_name|
-            fixtures_map[table_name] = Fixtures.new(connection, table_name.tr('/', '_'), class_names[table_name.tr('/', '_').to_sym], File.join(fixtures_directory, table_name))
-          end
+    unless files_to_read.empty?
+      connection.disable_referential_integrity do
+        fixtures_map = {}
+
+        fixture_files = files_to_read.map do |path|
+          table_name = path.tr '/', '_'
+
+          fixtures_map[path] = Fixtures.new(
+            connection,
+            table_name,
+            class_names[table_name.to_sym],
+            File.join(fixtures_directory, path))
+        end
 
-          all_loaded_fixtures.update(fixtures_map)
+        all_loaded_fixtures.update(fixtures_map)
 
-          connection.transaction(:requires_new => true) do
-            fixtures.reverse.each { |fixture| fixture.delete_existing_fixtures }
-            fixtures.each { |fixture| fixture.insert_fixtures }
+        connection.transaction(:requires_new => true) do
+          fixture_files.each do |ff|
+            conn = ff.model_class.respond_to?(:connection) ? ff.model_class.connection : connection
+            table_rows = ff.table_rows
 
-            # Cap primary key sequences to max(pk).
-            if connection.respond_to?(:reset_pk_sequence!)
-              table_names.each do |table_name|
-                connection.reset_pk_sequence!(table_name.tr('/', '_'))
+            table_rows.keys.each do |table|
+              conn.delete "DELETE FROM #{conn.quote_table_name(table)}", 'Fixture Delete'
+            end
+
+            table_rows.each do |table_name,rows|
+              rows.each do |row|
+                conn.insert_fixture(row, table_name)
               end
             end
           end
 
-          cache_fixtures(connection, fixtures_map)
+          # Cap primary key sequences to max(pk).
+          if connection.respond_to?(:reset_pk_sequence!)
+            table_names.each do |table_name|
+              connection.reset_pk_sequence!(table_name.tr('/', '_'))
+            end
+          end
         end
+
+        cache_fixtures(connection, fixtures_map)
       end
     end
     cached_fixtures(connection, table_names)
@@ -546,40 +565,60 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
     Zlib.crc32(label.to_s) % MAX_ID
   end
 
-  attr_reader :table_name, :name
+  attr_reader :table_name, :name, :fixtures, :model_class
 
   def initialize(connection, table_name, class_name, fixture_path, file_filter = DEFAULT_FILTER_RE)
-    @connection, @table_name, @fixture_path, @file_filter = connection, table_name, fixture_path, file_filter
-    @name = table_name # preserve fixture base name
-    @class_name = class_name ||
-                  (ActiveRecord::Base.pluralize_table_names ? @table_name.singularize.camelize : @table_name.camelize)
-    @table_name = "#{ActiveRecord::Base.table_name_prefix}#{@table_name}#{ActiveRecord::Base.table_name_suffix}"
-    @table_name = class_name.table_name if class_name.respond_to?(:table_name)
-    @connection = class_name.connection if class_name.respond_to?(:connection)
+    @connection   = connection
+    @table_name   = table_name
+    @fixture_path = fixture_path
+    @file_filter  = file_filter
+    @name         = table_name # preserve fixture base name
+    @class_name   = class_name
+
+    @fixtures     = ActiveSupport::OrderedHash.new
+    @table_name   = "#{ActiveRecord::Base.table_name_prefix}#{@table_name}#{ActiveRecord::Base.table_name_suffix}"
+
+    # Should be an AR::Base type class
+    if class_name.is_a?(Class)
+      @table_name   = class_name.table_name
+      @connection   = class_name.connection
+      @model_class  = class_name
+    else
+      @model_class  = class_name.constantize rescue nil
+    end
+
     read_fixture_files
   end
 
-  def delete_existing_fixtures
-    @connection.delete "DELETE FROM #{@connection.quote_table_name(table_name)}", 'Fixture Delete'
+  def [](x)
+    fixtures[x]
+  end
+
+  def []=(k,v)
+    fixtures[k] = v
+  end
+
+  def each(&block)
+    fixtures.each(&block)
+  end
+
+  def size
+    fixtures.size
   end
 
-  def insert_fixtures
+  # Return a hash of rows to be inserted.  The key is the table, the value is
+  # a list of rows to insert to that table.
+  def table_rows
     now = ActiveRecord::Base.default_timezone == :utc ? Time.now.utc : Time.now
     now = now.to_s(:db)
 
     # allow a standard key to be used for doing defaults in YAML
-    if is_a?(Hash)
-      delete('DEFAULTS')
-    else
-      delete(assoc('DEFAULTS'))
-    end
+    fixtures.delete('DEFAULTS')
 
     # track any join tables we need to insert later
-    habtm_fixtures = Hash.new do |h, habtm|
-      h[habtm] = HabtmFixtures.new(@connection, habtm.options[:join_table], nil, nil)
-    end
+    rows = Hash.new { |h,table| h[table] = [] }
 
-    each do |label, fixture|
+    rows[table_name] = fixtures.map do |label, fixture|
       row = fixture.to_hash
 
       if model_class && model_class < ActiveRecord::Base
@@ -615,14 +654,9 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
             fk_name = (association.options[:foreign_key] || "#{association.name}_id").to_s
 
             if association.name.to_s != fk_name && value = row.delete(association.name.to_s)
-              if association.options[:polymorphic]
-                if value.sub!(/\s*\(([^\)]*)\)\s*$/, "")
-                  target_type = $1
-                  target_type_name = (association.options[:foreign_type] || "#{association.name}_type").to_s
-
-                  # support polymorphic belongs_to as "label (Type)"
-                  row[target_type_name] = target_type
-                end
+              if association.options[:polymorphic] && value.sub!(/\s*\(([^\)]*)\)\s*$/, "")
+                # support polymorphic belongs_to as "label (Type)"
+                row[association.foreign_type] = $1
               end
 
               row[fk_name] = Fixtures.identify(value)
@@ -630,47 +664,22 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
           when :has_and_belongs_to_many
             if (targets = row.delete(association.name.to_s))
               targets = targets.is_a?(Array) ? targets : targets.split(/\s*,\s*/)
-              join_fixtures = habtm_fixtures[association]
-
-              targets.each do |target|
-                join_fixtures["#{label}_#{target}"] = Fixture.new(
-                  { association.primary_key_name => row[primary_key_name],
-                    association.association_foreign_key => Fixtures.identify(target) },
-                  nil, @connection)
-              end
+              table_name = association.options[:join_table]
+              rows[table_name].concat targets.map { |target|
+                { association.foreign_key             => row[primary_key_name],
+                  association.association_foreign_key => Fixtures.identify(target) }
+              }
             end
           end
         end
       end
 
-      @connection.insert_fixture(fixture, @table_name)
-    end
-
-    # insert any HABTM join tables we discovered
-    habtm_fixtures.values.each do |fixture|
-      fixture.delete_existing_fixtures
-      fixture.insert_fixtures
+      row
     end
+    rows
   end
 
   private
-    class HabtmFixtures < ::Fixtures #:nodoc:
-      def read_fixture_files; end
-    end
-
-    def model_class
-      unless defined?(@model_class)
-        @model_class =
-          if @class_name.nil? || @class_name.is_a?(Class)
-            @class_name
-          else
-            @class_name.constantize rescue nil
-          end
-      end
-
-      @model_class
-    end
-
     def primary_key_name
       @primary_key_name ||= model_class && model_class.primary_key
     end
@@ -724,7 +733,7 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
               raise Fixture::FormatError, "Bad data for #{@class_name} fixture named #{name} (nil)"
             end
 
-            self[name] = Fixture.new(data, model_class, @connection)
+            fixtures[name] = Fixture.new(data, model_class)
           end
         end
       end
@@ -737,7 +746,7 @@ class Fixtures < (RUBY_VERSION < '1.9' ? YAML::Omap : Hash)
       reader.each do |row|
         data = {}
         row.each_with_index { |cell, j| data[header[j].to_s.strip] = cell.to_s.strip }
-        self["#{@class_name.to_s.underscore}_#{i+=1}"] = Fixture.new(data, model_class, @connection)
+        fixtures["#{@class_name.to_s.underscore}_#{i+=1}"] = Fixture.new(data, model_class)
       end
     end
 
@@ -773,44 +782,30 @@ class Fixture #:nodoc:
   class FormatError < FixtureError #:nodoc:
   end
 
-  attr_reader :model_class
+  attr_reader :model_class, :fixture
 
-  def initialize(fixture, model_class, connection = ActiveRecord::Base.connection)
-    @connection = connection
-    @fixture = fixture
-    @model_class = model_class.is_a?(Class) ? model_class : model_class.constantize rescue nil
+  def initialize(fixture, model_class)
+    @fixture     = fixture
+    @model_class = model_class
   end
 
   def class_name
-    @model_class.name if @model_class
+    model_class.name if model_class
   end
 
   def each
-    @fixture.each { |item| yield item }
+    fixture.each { |item| yield item }
   end
 
   def [](key)
-    @fixture[key]
+    fixture[key]
   end
 
-  def to_hash
-    @fixture
-  end
-
-  def key_list
-    @fixture.keys.map { |column_name| @connection.quote_column_name(column_name) }.join(', ')
-  end
-
-  def value_list
-    cols = (model_class && model_class < ActiveRecord::Base) ? model_class.columns_hash : {}
-    @fixture.map do |key, value|
-      @connection.quote(value, cols[key]).gsub('[^\]\\n', "\n").gsub('[^\]\\r', "\r")
-    end.join(', ')
-  end
+  alias :to_hash :fixture
 
   def find
     if model_class
-      model_class.find(self[model_class.primary_key])
+      model_class.find(fixture[model_class.primary_key])
     else
       raise FixtureClassNotFound, "No class attached to find."
     end
@@ -837,7 +832,9 @@ module ActiveRecord
       self.use_instantiated_fixtures = false
       self.pre_loaded_fixtures = false
 
-      self.fixture_class_names = {}
+      self.fixture_class_names = Hash.new do |h, table_name|
+        h[table_name] = Fixtures.find_table_name(table_name)
+      end
     end
 
     module ClassMethods
@@ -937,7 +934,7 @@ module ActiveRecord
         if @@already_loaded_fixtures[self.class]
           @loaded_fixtures = @@already_loaded_fixtures[self.class]
         else
-          load_fixtures
+          @loaded_fixtures = load_fixtures
           @@already_loaded_fixtures[self.class] = @loaded_fixtures
         end
         ActiveRecord::Base.connection.increment_open_transactions
@@ -947,7 +944,7 @@ module ActiveRecord
       else
         Fixtures.reset_cache
         @@already_loaded_fixtures[self.class] = nil
-        load_fixtures
+        @loaded_fixtures = load_fixtures
       end
 
       # Instantiate fixtures for every test if requested.
@@ -971,15 +968,8 @@ module ActiveRecord
 
     private
       def load_fixtures
-        @loaded_fixtures = {}
         fixtures = Fixtures.create_fixtures(fixture_path, fixture_table_names, fixture_class_names)
-        unless fixtures.nil?
-          if fixtures.instance_of?(Fixtures)
-            @loaded_fixtures[fixtures.name] = fixtures
-          else
-            fixtures.each { |f| @loaded_fixtures[f.name] = f }
-          end
-        end
+        Hash[fixtures.map { |f| [f.name, f] }]
       end
 
       # for pre_loaded_fixtures, only require the classes once. huge speed improvement
diff --git a/activerecord/lib/active_record/identity_map.rb b/activerecord/lib/active_record/identity_map.rb
index 438287d3ea..6718a92e13 100644
--- a/activerecord/lib/active_record/identity_map.rb
+++ b/activerecord/lib/active_record/identity_map.rb
@@ -81,7 +81,9 @@ module ActiveRecord
         @changed_attributes.update(coder['attributes'].slice(*dirty))
         @changed_attributes.delete_if{|k,v| v.eql? @attributes[k]}
 
-        _run_find_callbacks
+        set_serialized_attributes
+
+        run_callbacks :find
 
         self
       end
diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb
index e5065de7fb..6b2b1ebafe 100644
--- a/activerecord/lib/active_record/locking/optimistic.rb
+++ b/activerecord/lib/active_record/locking/optimistic.rb
@@ -58,6 +58,12 @@ module ActiveRecord
       end
 
       private
+        def increment_lock
+          lock_col = self.class.locking_column
+          previous_lock_value = send(lock_col).to_i
+          send(lock_col + '=', previous_lock_value + 1)
+        end
+
         def attributes_from_column_definition
           result = super
 
@@ -78,8 +84,8 @@ module ActiveRecord
           return 0 if attribute_names.empty?
 
           lock_col = self.class.locking_column
-          previous_value = send(lock_col).to_i
-          send(lock_col + '=', previous_value + 1)
+          previous_lock_value = send(lock_col).to_i
+          increment_lock
 
           attribute_names += [lock_col]
           attribute_names.uniq!
@@ -89,7 +95,7 @@ module ActiveRecord
 
             stmt = relation.where(
               relation.table[self.class.primary_key].eq(quoted_id).and(
-                relation.table[lock_col].eq(quote_value(previous_value))
+                relation.table[lock_col].eq(quote_value(previous_lock_value))
               )
             ).arel.compile_update(arel_attributes_values(false, false, attribute_names))
 
@@ -103,7 +109,7 @@ module ActiveRecord
 
           # If something went wrong, revert the version.
           rescue Exception
-            send(lock_col + '=', previous_value)
+            send(lock_col + '=', previous_lock_value)
             raise
           end
         end
diff --git a/activerecord/lib/active_record/log_subscriber.rb b/activerecord/lib/active_record/log_subscriber.rb
index c7ae12977a..afadbf03ef 100644
--- a/activerecord/lib/active_record/log_subscriber.rb
+++ b/activerecord/lib/active_record/log_subscriber.rb
@@ -22,8 +22,16 @@ module ActiveRecord
       self.class.runtime += event.duration
       return unless logger.debug?
 
-      name = '%s (%.1fms)' % [event.payload[:name], event.duration]
-      sql  = event.payload[:sql].squeeze(' ')
+      payload = event.payload
+      name    = '%s (%.1fms)' % [payload[:name], event.duration]
+      sql     = payload[:sql].squeeze(' ')
+      binds   = nil
+
+      unless (payload[:binds] || []).empty?
+        binds = "  " + payload[:binds].map { |col,v|
+          [col.name, v]
+        }.inspect
+      end
 
       if odd?
         name = color(name, CYAN, true)
@@ -32,7 +40,7 @@ module ActiveRecord
         name = color(name, MAGENTA, true)
       end
 
-      debug "  #{name}  #{sql}"
+      debug "  #{name}  #{sql}#{binds}"
     end
 
     def odd?
@@ -45,4 +53,4 @@ module ActiveRecord
   end
 end
 
-ActiveRecord::LogSubscriber.attach_to :active_record
\ No newline at end of file
+ActiveRecord::LogSubscriber.attach_to :active_record
diff --git a/activerecord/lib/active_record/migration/command_recorder.rb b/activerecord/lib/active_record/migration/command_recorder.rb
index d7e481905a..c9d57ce812 100644
--- a/activerecord/lib/active_record/migration/command_recorder.rb
+++ b/activerecord/lib/active_record/migration/command_recorder.rb
@@ -40,7 +40,7 @@ module ActiveRecord
         @commands.reverse.map { |name, args|
           method = :"invert_#{name}"
           raise IrreversibleMigration unless respond_to?(method, true)
-          __send__(method, args)
+          send(method, args)
         }
       end
 
@@ -48,12 +48,16 @@ module ActiveRecord
         super || delegate.respond_to?(*args)
       end
 
-      def send(method, *args) # :nodoc:
-        return super unless respond_to?(method)
-        record(method, args)
+      [:create_table, :rename_table, :add_column, :remove_column, :rename_index, :rename_column, :add_index, :remove_index, :add_timestamps, :remove_timestamps, :change_column, :change_column_default].each do |method|
+        class_eval <<-EOV, __FILE__, __LINE__ + 1
+          def #{method}(*args)
+            record(:"#{method}", args)
+          end
+        EOV
       end
 
       private
+
       def invert_create_table(args)
         [:drop_table, args]
       end
@@ -86,6 +90,14 @@ module ActiveRecord
       def invert_add_timestamps(args)
         [:remove_timestamps, args]
       end
+
+      # Forwards any missing method call to the \target.
+      def method_missing(method, *args, &block)
+        @delegate.send(method, *args, &block)
+      rescue NoMethodError => e
+        raise e, e.message.sub(/ for #<.*$/, " via proxy for #{@delegate}")
+      end
+
     end
   end
 end
diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index 0a073ad6c8..52bdadcbb4 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -410,8 +410,20 @@ module ActiveRecord
             assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy])
           end
         elsif existing_record = existing_records.detect { |record| record.id.to_s == attributes['id'].to_s }
+          unless association.loaded? || call_reject_if(association_name, attributes)
+            # Make sure we are operating on the actual object which is in the association's
+            # proxy_target array (either by finding it, or adding it if not found)
+            target_record = association.proxy_target.detect { |record| record == existing_record }
+
+            if target_record
+              existing_record = target_record
+            else
+              association.send(:add_to_target, existing_record)
+            end
+
+          end
+
           if !call_reject_if(association_name, attributes)
-            association.send(:add_record_to_target_with_callbacks, existing_record) if !association.loaded?
             assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy])
           end
         else
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 78e84c73ee..df7b22080c 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -233,6 +233,7 @@ module ActiveRecord
     def touch(name = nil)
       attributes = timestamp_attributes_for_update_in_model
       attributes << name if name
+
       unless attributes.empty?
         current_time = current_time_from_proper_timezone
         changes = {}
@@ -241,6 +242,8 @@ module ActiveRecord
           changes[column.to_s] = write_attribute(column.to_s, current_time)
         end
 
+        changes[self.class.locking_column] = increment_lock if locking_enabled?
+
         @changed_attributes.except!(*changes.keys)
         primary_key = self.class.primary_key
         self.class.update_all(changes, { primary_key => self[primary_key] }) == 1
@@ -267,11 +270,11 @@ module ActiveRecord
     # Creates a record with values matching those of the instance attributes
     # and returns its id.
     def create
-      if self.id.nil? && connection.prefetch_primary_key?(self.class.table_name)
+      if id.nil? && connection.prefetch_primary_key?(self.class.table_name)
         self.id = connection.next_sequence_value(self.class.sequence_name)
       end
 
-      attributes_values = arel_attributes_values
+      attributes_values = arel_attributes_values(!id.nil?)
 
       new_id = if attributes_values.empty?
         self.class.unscoped.insert connection.empty_insert_statement_value
@@ -292,7 +295,7 @@ module ActiveRecord
     # that instances loaded from the database would.
     def attributes_from_column_definition
       Hash[self.class.columns.map do |column|
-        [column.name, column.default] unless column.name == self.class.primary_key
+        [column.name, column.default]
       end]
     end
   end
diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb
index a634153d6f..cace6f0cc0 100644
--- a/activerecord/lib/active_record/railtie.rb
+++ b/activerecord/lib/active_record/railtie.rb
@@ -77,6 +77,7 @@ module ActiveRecord
       ActiveSupport.on_load(:active_record) do
         ActionDispatch::Reloader.to_cleanup do
           ActiveRecord::Base.clear_reloadable_connections!
+          ActiveRecord::Base.clear_cache!
         end
       end
     end
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index a4fc18148e..ff36814684 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -193,7 +193,7 @@ db_namespace = namespace :db do
       file_list = []
       Dir.foreach(File.join(Rails.root, 'db', 'migrate')) do |file|
         # only files matching "20091231235959_some_name.rb" pattern
-        if match_data = /(\d{14})_(.+)\.rb/.match(file)
+        if match_data = /^(\d{14})_(.+)\.rb$/.match(file)
           status = db_list.delete(match_data[1]) ? 'up' : 'down'
           file_list << [status, match_data[1], match_data[2]]
         end
@@ -296,8 +296,8 @@ db_namespace = namespace :db do
       base_dir = ENV['FIXTURES_PATH'] ? File.join(Rails.root, ENV['FIXTURES_PATH']) : File.join(Rails.root, 'test', 'fixtures')
       fixtures_dir = ENV['FIXTURES_DIR'] ? File.join(base_dir, ENV['FIXTURES_DIR']) : base_dir
 
-      (ENV['FIXTURES'] ? ENV['FIXTURES'].split(/,/).map {|f| File.join(fixtures_dir, f) } : Dir["#{fixtures_dir}/**/*.{yml,csv}"]).each do |fixture_file|
-        Fixtures.create_fixtures(fixtures_dir, fixture_file[(fixtures_dir.size + 1)..-5])
+      (ENV['FIXTURES'] ? ENV['FIXTURES'].split(/,/) : Dir["#{fixtures_dir}/**/*.{yml,csv}"].map {|f| f[(fixtures_dir.size + 1)..-5] }).each do |fixture_file|
+        Fixtures.create_fixtures(fixtures_dir, fixture_file)
       end
     end
 
@@ -409,7 +409,7 @@ db_namespace = namespace :db do
         ENV['PGHOST']     = abcs["test"]["host"] if abcs["test"]["host"]
         ENV['PGPORT']     = abcs["test"]["port"].to_s if abcs["test"]["port"]
         ENV['PGPASSWORD'] = abcs["test"]["password"].to_s if abcs["test"]["password"]
-        `psql -U "#{abcs["test"]["username"]}" -f #{Rails.root}/db/#{Rails.env}_structure.sql #{abcs["test"]["database"]}`
+        `psql -U "#{abcs["test"]["username"]}" -f #{Rails.root}/db/#{Rails.env}_structure.sql #{abcs["test"]["database"]} #{abcs["test"]["template"]}`
       when "sqlite", "sqlite3"
         dbfile = abcs["test"]["database"] || abcs["test"]["dbfile"]
         `#{abcs["test"]["adapter"]} #{dbfile} < #{Rails.root}/db/#{Rails.env}_structure.sql`
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index b9caa64a0e..ceeb0ec39d 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -1,4 +1,5 @@
 require 'active_support/core_ext/class/attribute'
+require 'active_support/core_ext/module/deprecation'
 
 module ActiveRecord
   # = Active Record Reflection
@@ -196,8 +197,17 @@ module ActiveRecord
         @quoted_table_name ||= klass.quoted_table_name
       end
 
+      def foreign_key
+        @foreign_key ||= options[:foreign_key] || derive_foreign_key
+      end
+
       def primary_key_name
-        @primary_key_name ||= options[:foreign_key] || derive_primary_key_name
+        foreign_key
+      end
+      deprecate :primary_key_name => :foreign_key
+
+      def foreign_type
+        @foreign_type ||= options[:foreign_type] || "#{name}_type"
       end
 
       def primary_key_column
@@ -208,6 +218,13 @@ module ActiveRecord
         @association_foreign_key ||= options[:association_foreign_key] || class_name.foreign_key
       end
 
+      def association_primary_key
+        @association_primary_key ||=
+          options[:primary_key] ||
+          !options[:polymorphic] && klass.primary_key ||
+          'id'
+      end
+
       def active_record_primary_key
         @active_record_primary_key ||= options[:primary_key] || active_record.primary_key
       end
@@ -244,7 +261,7 @@ module ActiveRecord
         false
       end
 
-      def through_reflection_primary_key_name
+      def through_reflection_foreign_key
       end
 
       def source_reflection
@@ -291,22 +308,36 @@ module ActiveRecord
         !options[:validate].nil? ? options[:validate] : (options[:autosave] == true || macro == :has_many)
       end
 
-      def dependent_conditions(record, base_class, extra_conditions)
-        dependent_conditions = []
-        dependent_conditions << "#{primary_key_name} = #{record.send(name).send(:owner_quoted_id)}"
-        dependent_conditions << "#{options[:as]}_type = '#{base_class.name}'" if options[:as]
-        dependent_conditions << klass.send(:sanitize_sql, options[:conditions]) if options[:conditions]
-        dependent_conditions << extra_conditions if extra_conditions
-        dependent_conditions = dependent_conditions.collect {|where| "(#{where})" }.join(" AND ")
-        dependent_conditions = dependent_conditions.gsub('@', '\@')
-        dependent_conditions
-      end
-
       # Returns +true+ if +self+ is a +belongs_to+ reflection.
       def belongs_to?
         macro == :belongs_to
       end
 
+      def proxy_class
+        case macro
+        when :belongs_to
+          if options[:polymorphic]
+            Associations::BelongsToPolymorphicAssociation
+          else
+            Associations::BelongsToAssociation
+          end
+        when :has_and_belongs_to_many
+          Associations::HasAndBelongsToManyAssociation
+        when :has_many
+          if options[:through]
+            Associations::HasManyThroughAssociation
+          else
+            Associations::HasManyAssociation
+          end
+        when :has_one
+          if options[:through]
+            Associations::HasOneThroughAssociation
+          else
+            Associations::HasOneAssociation
+          end
+        end
+      end
+
       private
         def derive_class_name
           class_name = name.to_s.camelize
@@ -314,7 +345,7 @@ module ActiveRecord
           class_name
         end
 
-        def derive_primary_key_name
+        def derive_foreign_key
           if belongs_to?
             "#{name}_id"
           elsif options[:as]
@@ -368,6 +399,10 @@ module ActiveRecord
           raise HasManyThroughAssociationNotFoundError.new(active_record.name, self)
         end
 
+        if through_reflection.options[:polymorphic]
+          raise HasManyThroughAssociationPolymorphicThroughError.new(active_record.name, self)
+        end
+
         if source_reflection.nil?
           raise HasManyThroughSourceAssociationNotFoundError.new(self)
         end
@@ -377,22 +412,26 @@ module ActiveRecord
         end
 
         if source_reflection.options[:polymorphic] && options[:source_type].nil?
-          raise HasManyThroughAssociationPolymorphicError.new(active_record.name, self, source_reflection)
+          raise HasManyThroughAssociationPolymorphicSourceError.new(active_record.name, self, source_reflection)
         end
 
         unless [:belongs_to, :has_many, :has_one].include?(source_reflection.macro) && source_reflection.options[:through].nil?
           raise HasManyThroughSourceAssociationMacroError.new(self)
         end
 
+        if macro == :has_one && through_reflection.collection?
+          raise HasOneThroughCantAssociateThroughCollection.new(active_record.name, self, through_reflection)
+        end
+
         check_validity_of_inverse!
       end
 
       def through_reflection_primary_key
-        through_reflection.belongs_to? ? through_reflection.klass.primary_key : through_reflection.primary_key_name
+        through_reflection.belongs_to? ? through_reflection.klass.primary_key : through_reflection.foreign_key
       end
 
-      def through_reflection_primary_key_name
-        through_reflection.primary_key_name if through_reflection.belongs_to?
+      def through_reflection_foreign_key
+        through_reflection.foreign_key if through_reflection.belongs_to?
       end
 
       private
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index c6943444a4..cb684c1109 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -10,7 +10,9 @@ module ActiveRecord
 
     include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches
 
+    # These are explicitly delegated to improve performance (avoids method_missing)
     delegate :to_xml, :to_yaml, :length, :collect, :map, :each, :all?, :include?, :to => :to_a
+    delegate :table_name, :primary_key, :to => :klass
 
     attr_reader :table, :klass, :loaded
     attr_accessor :extensions
@@ -30,13 +32,19 @@ module ActiveRecord
     def insert(values)
       im = arel.compile_insert values
       im.into @table
-      primary_key_name = @klass.primary_key
-      primary_key_value = Hash === values ? values[primary_key_name] : nil
+
+      primary_key_value = nil
+
+      if primary_key && Hash === values
+        primary_key_value = values[values.keys.find { |k|
+          k.name == primary_key
+        }]
+      end
 
       @klass.connection.insert(
         im.to_sql,
         'SQL',
-        primary_key_name,
+        primary_key,
         primary_key_value)
     end
 
@@ -172,13 +180,19 @@ module ActiveRecord
       if conditions || options.present?
         where(conditions).apply_finder_options(options.slice(:limit, :order)).update_all(updates)
       else
+        limit = nil
+        order = []
         # Apply limit and order only if they're both present
         if @limit_value.present? == @order_values.present?
-          stmt = arel.compile_update(Arel::SqlLiteral.new(@klass.send(:sanitize_sql_for_assignment, updates)))
-          @klass.connection.update stmt.to_sql
-        else
-          except(:limit, :order).update_all(updates)
+          limit = arel.limit
+          order = arel.orders
         end
+
+        stmt = arel.compile_update(Arel.sql(@klass.send(:sanitize_sql_for_assignment, updates)))
+        stmt.take limit
+        stmt.order(*order)
+        stmt.key = table[primary_key]
+        @klass.connection.update stmt.to_sql
       end
     end
 
@@ -320,7 +334,7 @@ module ActiveRecord
     #   # Delete multiple rows
     #   Todo.delete([2,3,4])
     def delete(id_or_array)
-      where(@klass.primary_key => id_or_array).delete_all
+      where(primary_key => id_or_array).delete_all
     end
 
     def reload
@@ -336,10 +350,6 @@ module ActiveRecord
       self
     end
 
-    def primary_key
-      @primary_key ||= table[@klass.primary_key]
-    end
-
     def to_sql
       @to_sql ||= arel.to_sql
     end
@@ -373,10 +383,6 @@ module ActiveRecord
       to_a.inspect
     end
 
-    def table_name
-      @klass.table_name
-    end
-
     protected
 
     def method_missing(method, *args, &block)
diff --git a/activerecord/lib/active_record/relation/batches.rb b/activerecord/lib/active_record/relation/batches.rb
index b41e935ed5..359af9820f 100644
--- a/activerecord/lib/active_record/relation/batches.rb
+++ b/activerecord/lib/active_record/relation/batches.rb
@@ -65,7 +65,7 @@ module ActiveRecord
       batch_size = options.delete(:batch_size) || 1000
 
       relation = relation.except(:order).order(batch_order).limit(batch_size)
-      records = relation.where(primary_key.gteq(start)).all
+      records = relation.where(table[primary_key].gteq(start)).all
 
       while records.any?
         yield records
@@ -73,7 +73,7 @@ module ActiveRecord
         break if records.size < batch_size
 
         if primary_key_offset = records.last.id
-          records = relation.where(primary_key.gt(primary_key_offset)).to_a
+          records = relation.where(table[primary_key].gt(primary_key_offset)).to_a
         else
           raise "Primary key not included in the custom select clause"
         end
@@ -83,7 +83,7 @@ module ActiveRecord
     private
 
     def batch_order
-      "#{@klass.table_name}.#{@klass.primary_key} ASC"
+      "#{table_name}.#{primary_key} ASC"
     end
   end
 end
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index fd45bb24dd..abc4c54109 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -168,7 +168,7 @@ module ActiveRecord
 
         unless arel.ast.grep(Arel::Nodes::OuterJoin).empty?
           distinct = true
-          column_name = @klass.primary_key if column_name == :all
+          column_name = primary_key if column_name == :all
         end
 
         distinct = nil if column_name =~ /\s*DISTINCT\s+/i
@@ -211,7 +211,7 @@ module ActiveRecord
       group_attr      = @group_values
       association     = @klass.reflect_on_association(group_attr.first.to_sym)
       associated      = group_attr.size == 1 && association && association.macro == :belongs_to # only count belongs_to associations
-      group_fields  = Array(associated ? association.primary_key_name : group_attr)
+      group_fields  = Array(associated ? association.foreign_key : group_attr)
       group_aliases = group_fields.map { |field| column_alias_for(field) }
       group_columns = group_aliases.zip(group_fields).map { |aliaz,field|
         [aliaz, column_for(field)]
@@ -282,15 +282,11 @@ module ActiveRecord
     end
 
     def type_cast_calculated_value(value, column, operation = nil)
-      if value.is_a?(String) || value.nil?
-        case operation
-          when 'count'   then value.to_i
-          when 'sum'     then type_cast_using_column(value || '0', column)
-          when 'average' then value.try(:to_d)
-          else type_cast_using_column(value, column)
-        end
-      else
-        type_cast_using_column(value, column)
+      case operation
+        when 'count'   then value.to_i
+        when 'sum'     then type_cast_using_column(value || '0', column)
+        when 'average' then value.respond_to?(:to_d) ? value.to_d : value
+        else type_cast_using_column(value, column)
       end
     end
 
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 8bc28c06cb..7f32e5538e 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -19,7 +19,7 @@ module ActiveRecord
     #
     # All approaches accept an options hash as their last parameter.
     #
-    # ==== Parameters
+    # ==== Options
     #
     # * <tt>:conditions</tt> - An SQL fragment like "administrator = 1", <tt>["user_name = ?", username]</tt>,
     #   or <tt>["user_name = :user_name", { :user_name => user_name }]</tt>. See conditions in the intro.
@@ -171,13 +171,13 @@ module ActiveRecord
     def exists?(id = nil)
       id = id.id if ActiveRecord::Base === id
 
-      relation = select(primary_key).limit(1)
+      relation = select("1").limit(1)
 
       case id
       when Array, Hash
         relation = relation.where(id)
       else
-        relation = relation.where(primary_key.eq(id)) if id
+        relation = relation.where(table[primary_key].eq(id)) if id
       end
 
       relation.first ? true : false
@@ -188,7 +188,8 @@ module ActiveRecord
     def find_with_associations
       including = (@eager_load_values + @includes_values).uniq
       join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(@klass, including, [])
-      rows = construct_relation_for_association_find(join_dependency).to_a
+      relation = construct_relation_for_association_find(join_dependency)
+      rows = connection.select_all(relation.to_sql, 'SQL', relation.bind_values)
       join_dependency.instantiate(rows)
     rescue ThrowResult
       []
@@ -225,10 +226,10 @@ module ActiveRecord
 
     def construct_limited_ids_condition(relation)
       orders = relation.order_values
-      values = @klass.connection.distinct("#{@klass.connection.quote_table_name @klass.table_name}.#{@klass.primary_key}", orders)
+      values = @klass.connection.distinct("#{@klass.connection.quote_table_name table_name}.#{primary_key}", orders)
 
-      ids_array = relation.select(values).collect {|row| row[@klass.primary_key]}
-      ids_array.empty? ? raise(ThrowResult) : primary_key.in(ids_array)
+      ids_array = relation.select(values).collect {|row| row[primary_key]}
+      ids_array.empty? ? raise(ThrowResult) : table[primary_key].in(ids_array)
     end
 
     def find_by_attributes(match, attributes, *args)
@@ -290,24 +291,24 @@ module ActiveRecord
     def find_one(id)
       id = id.id if ActiveRecord::Base === id
 
-      column = columns_hash[primary_key.name.to_s]
+      column = columns_hash[primary_key]
 
       substitute = connection.substitute_for(column, @bind_values)
-      relation = where(primary_key.eq(substitute))
+      relation = where(table[primary_key].eq(substitute))
       relation.bind_values = [[column, id]]
       record = relation.first
 
       unless record
         conditions = arel.where_sql
         conditions = " [#{conditions}]" if conditions
-        raise RecordNotFound, "Couldn't find #{@klass.name} with #{@klass.primary_key}=#{id}#{conditions}"
+        raise RecordNotFound, "Couldn't find #{@klass.name} with #{primary_key}=#{id}#{conditions}"
       end
 
       record
     end
 
     def find_some(ids)
-      result = where(primary_key.in(ids)).all
+      result = where(table[primary_key].in(ids)).all
 
       expected_size =
         if @limit_value && ids.size > @limit_value
diff --git a/activerecord/lib/active_record/relation/predicate_builder.rb b/activerecord/lib/active_record/relation/predicate_builder.rb
index 70d84619a1..61d9974570 100644
--- a/activerecord/lib/active_record/relation/predicate_builder.rb
+++ b/activerecord/lib/active_record/relation/predicate_builder.rb
@@ -15,18 +15,18 @@ module ActiveRecord
             table = Arel::Table.new(table_name, :engine => engine)
           end
 
-          attribute = table[column] || Arel::Attribute.new(table, column)
+          attribute = table[column.to_sym]
 
           case value
           when Array, ActiveRecord::Associations::AssociationCollection, ActiveRecord::Relation
             values = value.to_a.map { |x|
-              x.respond_to?(:quoted_id) ? x.quoted_id : x
+              x.is_a?(ActiveRecord::Base) ? x.id : x
             }
             attribute.in(values)
           when Range, Arel::Relation
             attribute.in(value)
           when ActiveRecord::Base
-            attribute.eq(Arel.sql(value.quoted_id))
+            attribute.eq(value.id)
           when Class
             # FIXME: I think we need to deprecate this behavior
             attribute.eq(value.name)
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index 0ab55ae864..6a905b8588 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -128,7 +128,7 @@ module ActiveRecord
 
     def create_with(value)
       relation = clone
-      relation.create_with_value = value
+      relation.create_with_value = value && (@create_with_value || {}).merge(value)
       relation
     end
 
@@ -152,7 +152,7 @@ module ActiveRecord
       order_clause = arel.order_clauses
 
       order = order_clause.empty? ?
-        "#{@klass.table_name}.#{@klass.primary_key} DESC" :
+        "#{table_name}.#{primary_key} DESC" :
         reverse_sql_order(order_clause).join(', ')
 
       except(:order).order(Arel.sql(order))
@@ -171,7 +171,7 @@ module ActiveRecord
 
       arel.having(*@having_values.uniq.reject{|h| h.blank?}) unless @having_values.empty?
 
-      arel.take(@limit_value) if @limit_value
+      arel.take(connection.sanitize_limit(@limit_value)) if @limit_value
       arel.skip(@offset_value) if @offset_value
 
       arel.group(*@group_values.uniq.reject{|g| g.blank?}) unless @group_values.empty?
diff --git a/activerecord/lib/active_record/relation/spawn_methods.rb b/activerecord/lib/active_record/relation/spawn_methods.rb
index 5acf3ec83a..4150e36a9a 100644
--- a/activerecord/lib/active_record/relation/spawn_methods.rb
+++ b/activerecord/lib/active_record/relation/spawn_methods.rb
@@ -46,21 +46,28 @@ module ActiveRecord
 
       merged_relation.where_values = merged_wheres
 
-      (Relation::SINGLE_VALUE_METHODS - [:lock]).each do |method|
+      (Relation::SINGLE_VALUE_METHODS - [:lock, :create_with]).each do |method|
         value = r.send(:"#{method}_value")
         merged_relation.send(:"#{method}_value=", value) unless value.nil?
       end
 
       merged_relation.lock_value = r.lock_value unless merged_relation.lock_value
 
+      merged_relation = merged_relation.create_with(r.create_with_value) if r.create_with_value
+
       # Apply scope extension modules
       merged_relation.send :apply_modules, r.extensions
 
       merged_relation
     end
 
-    alias :& :merge
-
+    # Removes from the query the condition(s) specified in +skips+.
+    #
+    # Example:
+    #
+    #   Post.order('id asc').except(:order)                  # discards the order condition
+    #   Post.where('id > 10').order('id asc').except(:where) # discards the where condition but keeps the order
+    #
     def except(*skips)
       result = self.class.new(@klass, table)
 
@@ -75,6 +82,13 @@ module ActiveRecord
       result
     end
 
+    # Removes any condition from the query other than the one(s) specified in +onlies+.
+    #
+    # Example:
+    #
+    #   Post.order('id asc').only(:where)         # discards the order condition
+    #   Post.order('id asc').only(:where, :order) # uses the specified order
+    #
     def only(*onlies)
       result = self.class.new(@klass, table)
 
@@ -98,7 +112,7 @@ module ActiveRecord
 
       options.assert_valid_keys(VALID_FIND_OPTIONS)
       finders = options.dup
-      finders.delete_if { |key, value| value.nil? }
+      finders.delete_if { |key, value| value.nil? && key != :limit }
 
       ([:joins, :select, :group, :order, :having, :limit, :offset, :from, :lock, :readonly] & finders.keys).each do |finder|
         relation = relation.send(finder, finders[finder])
diff --git a/activerecord/lib/active_record/result.rb b/activerecord/lib/active_record/result.rb
index 8deff1478f..0465b21e88 100644
--- a/activerecord/lib/active_record/result.rb
+++ b/activerecord/lib/active_record/result.rb
@@ -20,10 +20,14 @@ module ActiveRecord
       hash_rows.each { |row| yield row }
     end
 
+    def to_hash
+      hash_rows
+    end
+
     private
     def hash_rows
       @hash_rows ||= @rows.map { |row|
-        ActiveSupport::OrderedHash[@columns.zip(row)]
+        Hash[@columns.zip(row)]
       }
     end
   end
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index e30b481fe1..a893c0ad85 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -83,7 +83,7 @@ HEADER
 
           # first dump primary key column
           if @connection.respond_to?(:pk_and_sequence_for)
-            pk, pk_seq = @connection.pk_and_sequence_for(table)
+            pk, _ = @connection.pk_and_sequence_for(table)
           elsif @connection.respond_to?(:primary_key)
             pk = @connection.primary_key(table)
           end
diff --git a/activerecord/lib/active_record/session_store.rb b/activerecord/lib/active_record/session_store.rb
index 3400fd6ade..7e77aefb21 100644
--- a/activerecord/lib/active_record/session_store.rb
+++ b/activerecord/lib/active_record/session_store.rb
@@ -59,10 +59,12 @@ module ActiveRecord
       end
 
       def drop_table!
+        connection_pool.clear_table_cache!(table_name)
         connection.drop_table table_name
       end
 
       def create_table!
+        connection_pool.clear_table_cache!(table_name)
         connection.create_table(table_name) do |t|
           t.string session_id_column, :limit => 255
           t.text data_column_name
diff --git a/activerecord/lib/active_record/timestamp.rb b/activerecord/lib/active_record/timestamp.rb
index 2ecbd906bd..1511c71ffc 100644
--- a/activerecord/lib/active_record/timestamp.rb
+++ b/activerecord/lib/active_record/timestamp.rb
@@ -9,24 +9,26 @@ module ActiveRecord
   #
   # Timestamping can be turned off by setting:
   #
-  #   <tt>ActiveRecord::Base.record_timestamps = false</tt>
+  #   config.active_record.record_timestamps = false
   #
   # Timestamps are in the local timezone by default but you can use UTC by setting:
   #
-  #   <tt>ActiveRecord::Base.default_timezone = :utc</tt>
+  #   config.active_record.default_timezone = :utc
   #
   # == Time Zone aware attributes
   #
   # By default, ActiveRecord::Base keeps all the datetime columns time zone aware by executing following code.
   #
-  #   ActiveRecord::Base.time_zone_aware_attributes = true
+  #   config.active_record.time_zone_aware_attributes = true
   #
   # This feature can easily be turned off by assigning value <tt>false</tt> .
   #
-  # If your attributes are time zone aware and you desire to skip time zone conversion for certain
-  # attributes then you can do following:
+  # If your attributes are time zone aware and you desire to skip time zone conversion to the current Time.zone
+  # when reading certain attributes then you can do following:
   #
-  #   Topic.skip_time_zone_conversion_for_attributes = [:written_on]
+  #   class Topic < ActiveRecord::Base
+  #     self.skip_time_zone_conversion_for_attributes = [:written_on]
+  #   end
   module Timestamp
     extend ActiveSupport::Concern
 
@@ -66,8 +68,16 @@ module ActiveRecord
       self.record_timestamps && (!partial_updates? || changed? || (attributes.keys & self.class.serialized_attributes.keys).present?)
     end
 
+    def timestamp_attributes_for_create_in_model
+      timestamp_attributes_for_create.select { |c| self.class.column_names.include?(c.to_s) }
+    end
+
     def timestamp_attributes_for_update_in_model
-      timestamp_attributes_for_update.select { |c| respond_to?(c) }
+      timestamp_attributes_for_update.select { |c| self.class.column_names.include?(c.to_s) }
+    end
+
+    def all_timestamp_attributes_in_model
+      timestamp_attributes_for_create_in_model + timestamp_attributes_for_update_in_model
     end
 
     def timestamp_attributes_for_update #:nodoc:
diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index de496698f1..60d4c256c4 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -260,7 +260,7 @@ module ActiveRecord
 
     # Call the after_commit callbacks
     def committed! #:nodoc:
-      _run_commit_callbacks
+      run_callbacks :commit
     ensure
       clear_transaction_record_state
     end
@@ -268,7 +268,7 @@ module ActiveRecord
     # Call the after rollback callbacks. The restore_state argument indicates if the record
     # state should be rolled back to the beginning or just to the last savepoint.
     def rolledback!(force_restore_state = false) #:nodoc:
-      _run_rollback_callbacks
+      run_callbacks :rollback
     ensure
       restore_transaction_record_state(force_restore_state)
     end
@@ -302,8 +302,8 @@ module ActiveRecord
     # Save the new record state and id of a record so it can be restored later if a transaction fails.
     def remember_transaction_record_state #:nodoc
       @_start_transaction_state ||= {}
+      @_start_transaction_state[:id] = id if has_attribute?(self.class.primary_key)
       unless @_start_transaction_state.include?(:new_record)
-        @_start_transaction_state[:id] = id if has_attribute?(self.class.primary_key)
         @_start_transaction_state[:new_record] = @new_record
       end
       unless @_start_transaction_state.include?(:destroyed)
@@ -326,16 +326,14 @@ module ActiveRecord
         @_start_transaction_state[:level] = (@_start_transaction_state[:level] || 0) - 1
         if @_start_transaction_state[:level] < 1
           restore_state = remove_instance_variable(:@_start_transaction_state)
-          if restore_state
-            @attributes = @attributes.dup if @attributes.frozen?
-            @new_record = restore_state[:new_record]
-            @destroyed  = restore_state[:destroyed]
-            if restore_state[:id]
-              self.id = restore_state[:id]
-            else
-              @attributes.delete(self.class.primary_key)
-              @attributes_cache.delete(self.class.primary_key)
-            end
+          @attributes = @attributes.dup if @attributes.frozen?
+          @new_record = restore_state[:new_record]
+          @destroyed  = restore_state[:destroyed]
+          if restore_state.has_key?(:id)
+            self.id = restore_state[:id]
+          else
+            @attributes.delete(self.class.primary_key)
+            @attributes_cache.delete(self.class.primary_key)
           end
         end
       end
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index f367315b22..26c1a9db93 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -37,7 +37,7 @@ module ActiveRecord
       end
     end
 
-    # The validation process on save can be skipped by passing false. The regular Base#save method is
+    # The validation process on save can be skipped by passing :validate => false. The regular Base#save method is
     # replaced with this when the validations module is mixed in, which it is by default.
     def save(options={})
       perform_validations(options) ? super : false
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index 853808eebf..a96796f9ff 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -15,8 +15,10 @@ module ActiveRecord
       def validate_each(record, attribute, value)
         finder_class = find_finder_class_for(record)
 
-        if value && record.class.serialized_attributes.key?(attribute.to_s)
-          value = YAML.dump value
+        coder = record.class.serialized_attributes[attribute.to_s]
+
+        if value && coder
+          value = coder.dump value
         end
 
         sql, params = mount_sql_and_params(finder_class, record.class.quoted_table_name, attribute, value)
@@ -85,11 +87,16 @@ module ActiveRecord
       # can be named "davidhh".
       #
       #   class Person < ActiveRecord::Base
-      #     validates_uniqueness_of :user_name, :scope => :account_id
+      #     validates_uniqueness_of :user_name
       #   end
       #
-      # It can also validate whether the value of the specified attributes are unique based on multiple
-      # scope parameters.  For example, making sure that a teacher can only be on the schedule once
+      # It can also validate whether the value of the specified attributes are unique based on a scope parameter:
+      #
+      #   class Person < ActiveRecord::Base
+      #     validates_uniqueness_of :user_name, :scope => :account_id
+      #   end 
+      #
+      # Or even multiple scope parameters.  For example, making sure that a teacher can only be on the schedule once
       # per semester for a particular class.
       #
       #   class TeacherSchedule < ActiveRecord::Base
diff --git a/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb b/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb
index 126b6f434b..ce8d7eed42 100644
--- a/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb
+++ b/activerecord/lib/rails/generators/active_record/migration/templates/migration.rb
@@ -1,4 +1,11 @@
 class <%= migration_class_name %> < ActiveRecord::Migration
+<%- if migration_action == 'add' -%>
+  def change
+<% attributes.each do |attribute| -%>
+    add_column :<%= table_name %>, :<%= attribute.name %>, :<%= attribute.type %>
+<%- end -%>
+  end
+<%- else -%>
   def up
 <% attributes.each do |attribute| -%>
   <%- if migration_action -%>
@@ -14,4 +21,5 @@ class <%= migration_class_name %> < ActiveRecord::Migration
   <%- end -%>
 <%- end -%>
   end
+<%- end -%>
 end
diff --git a/activerecord/lib/rails/generators/active_record/model/model_generator.rb b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
index c75abd043c..f7caa43ac8 100644
--- a/activerecord/lib/rails/generators/active_record/model/model_generator.rb
+++ b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
@@ -10,6 +10,7 @@ module ActiveRecord
       class_option :migration,  :type => :boolean
       class_option :timestamps, :type => :boolean
       class_option :parent,     :type => :string, :desc => "The parent class for the generated model"
+      class_option :indexes,    :type => :boolean, :default => true, :desc => "Add indexes for references and belongs_to columns"
 
       def create_migration_file
         return unless options[:migration] && options[:parent].nil?
diff --git a/activerecord/lib/rails/generators/active_record/model/templates/migration.rb b/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
index 7d4e1a7404..4f81a52fd0 100644
--- a/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
+++ b/activerecord/lib/rails/generators/active_record/model/templates/migration.rb
@@ -1,5 +1,5 @@
 class <%= migration_class_name %> < ActiveRecord::Migration
-  def up
+  def change
     create_table :<%= table_name %> do |t|
 <% for attribute in attributes -%>
       t.<%= attribute.type %> :<%= attribute.name %>
@@ -8,13 +8,10 @@ class <%= migration_class_name %> < ActiveRecord::Migration
       t.timestamps
 <% end -%>
     end
-
+<% if options[:indexes] -%>
 <% attributes.select {|attr| attr.reference? }.each do |attribute| -%>
     add_index :<%= table_name %>, :<%= attribute.name %>_id
 <% end -%>
-  end
-
-  def down
-    drop_table :<%= table_name %>
+<% end -%>
   end
 end
diff --git a/activerecord/test/active_record/connection_adapters/fake_adapter.rb b/activerecord/test/active_record/connection_adapters/fake_adapter.rb
new file mode 100644
index 0000000000..1c2942170e
--- /dev/null
+++ b/activerecord/test/active_record/connection_adapters/fake_adapter.rb
@@ -0,0 +1,36 @@
+module ActiveRecord
+  class Base
+    def self.fake_connection(config)
+      ConnectionAdapters::FakeAdapter.new nil, logger
+    end
+  end
+
+  module ConnectionAdapters
+    class FakeAdapter < AbstractAdapter
+      attr_accessor :tables, :primary_keys
+
+      def initialize(connection, logger)
+        super
+        @tables       = []
+        @primary_keys = {}
+        @columns      = Hash.new { |h,k| h[k] = [] }
+      end
+
+      def primary_key(table)
+        @primary_keys[table]
+      end
+
+      def merge_column(table_name, name, sql_type = nil, options = {})
+        @columns[table_name] << ActiveRecord::ConnectionAdapters::Column.new(
+          name.to_s,
+          options[:default],
+          sql_type.to_s,
+          options[:null])
+      end
+
+      def columns(table_name, message)
+        @columns[table_name]
+      end
+    end
+  end
+end
diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index 646aa88d80..49b2e945c3 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -141,16 +141,4 @@ class AdapterTest < ActiveRecord::TestCase
       end
     end
   end
-
-  def test_add_limit_offset_should_sanitize_sql_injection_for_limit_without_comas
-    sql_inject = "1 select * from schema"
-    assert_no_match(/schema/, @connection.add_limit_offset!("", :limit=>sql_inject))
-    assert_no_match(/schema/, @connection.add_limit_offset!("", :limit=>sql_inject, :offset=>7))
-  end
-
-  def test_add_limit_offset_should_sanitize_sql_injection_for_limit_with_comas
-    sql_inject = "1, 7 procedure help()"
-    assert_no_match(/procedure/, @connection.add_limit_offset!("", :limit=>sql_inject))
-    assert_no_match(/procedure/, @connection.add_limit_offset!("", :limit=>sql_inject, :offset=>7))
-  end
 end
diff --git a/activerecord/test/cases/adapters/mysql/reserved_word_test.rb b/activerecord/test/cases/adapters/mysql/reserved_word_test.rb
index 90d8b0d923..43015098c9 100644
--- a/activerecord/test/cases/adapters/mysql/reserved_word_test.rb
+++ b/activerecord/test/cases/adapters/mysql/reserved_word_test.rb
@@ -78,24 +78,6 @@ class MysqlReservedWordTest < ActiveRecord::TestCase
   self.use_instantiated_fixtures = true
   self.use_transactional_fixtures = false
 
-  #fixtures :group
-
-  def test_fixtures
-    f = create_test_fixtures :select, :distinct, :group, :values, :distincts_selects
-
-    assert_nothing_raised {
-      f.each do |x|
-        x.delete_existing_fixtures
-      end
-    }
-
-    assert_nothing_raised {
-      f.each do |x|
-        x.insert_fixtures
-      end
-    }
-  end
-
   #activerecord model class with reserved-word table name
   def test_activerecord_model
     create_test_fixtures :select, :distinct, :group, :values, :distincts_selects
@@ -105,9 +87,9 @@ class MysqlReservedWordTest < ActiveRecord::TestCase
     assert_nothing_raised { x.save }
     x.order = 'y'
     assert_nothing_raised { x.save }
-    assert_nothing_raised { y = Group.find_by_order('y') }
-    assert_nothing_raised { y = Group.find(1) }
-    x = Group.find(1)
+    assert_nothing_raised { Group.find_by_order('y') }
+    assert_nothing_raised { Group.find(1) }
+    Group.find(1)
   end
 
   # has_one association with reserved-word table name
diff --git a/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb b/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
index 90d8b0d923..1efa7deaeb 100644
--- a/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
@@ -78,24 +78,6 @@ class MysqlReservedWordTest < ActiveRecord::TestCase
   self.use_instantiated_fixtures = true
   self.use_transactional_fixtures = false
 
-  #fixtures :group
-
-  def test_fixtures
-    f = create_test_fixtures :select, :distinct, :group, :values, :distincts_selects
-
-    assert_nothing_raised {
-      f.each do |x|
-        x.delete_existing_fixtures
-      end
-    }
-
-    assert_nothing_raised {
-      f.each do |x|
-        x.insert_fixtures
-      end
-    }
-  end
-
   #activerecord model class with reserved-word table name
   def test_activerecord_model
     create_test_fixtures :select, :distinct, :group, :values, :distincts_selects
diff --git a/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb b/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
index 234696adeb..b8abdface4 100644
--- a/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb
@@ -9,6 +9,11 @@ module ActiveRecord
                                        :timeout => 100
       end
 
+      def test_primary_key_returns_nil_for_no_pk
+        @conn.exec_query('create table ex(id int, data string)')
+        assert_nil @conn.primary_key('ex')
+      end
+
       def test_connection_no_db
         assert_raises(ArgumentError) do
           Base.sqlite3_connection {}
diff --git a/activerecord/test/cases/associations/association_proxy_test.rb b/activerecord/test/cases/associations/association_proxy_test.rb
new file mode 100644
index 0000000000..55d8da4c4e
--- /dev/null
+++ b/activerecord/test/cases/associations/association_proxy_test.rb
@@ -0,0 +1,52 @@
+require "cases/helper"
+
+module ActiveRecord
+  module Associations
+    class AsssociationProxyTest < ActiveRecord::TestCase
+      class FakeOwner
+        attr_accessor :new_record
+        alias :new_record? :new_record
+
+        def initialize
+          @new_record = false
+        end
+      end
+
+      class FakeReflection < Struct.new(:options, :klass)
+        def initialize options = {}, klass = nil
+          super
+        end
+
+        def check_validity!
+          true
+        end
+      end
+
+      class FakeTarget
+      end
+
+      class FakeTargetProxy < AssociationProxy
+        def association_scope
+          true
+        end
+
+        def find_target
+          FakeTarget.new
+        end
+      end
+
+      def test_method_missing_error
+        reflection = FakeReflection.new({}, Object.new)
+        owner      = FakeOwner.new
+        proxy      = FakeTargetProxy.new(owner, reflection)
+
+        exception = assert_raises(NoMethodError) do
+          proxy.omg
+        end
+
+        assert_match('omg', exception.message)
+        assert_match(FakeTarget.name, exception.message)
+      end
+    end
+  end
+end
diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index 1820f95261..01073bca3d 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -17,7 +17,7 @@ require 'models/essay'
 class BelongsToAssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :companies, :developers, :projects, :topics,
            :developers_projects, :computers, :authors, :author_addresses,
-           :posts, :tags, :taggings, :comments
+           :posts, :tags, :taggings, :comments, :sponsors, :members
 
   def test_belongs_to
     Client.find(3).firm.name
@@ -78,27 +78,14 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     Firm.create("name" => "Apple")
     Client.create("name" => "Citibank", :firm_name => "Apple")
     citibank_result = Client.find(:first, :conditions => {:name => "Citibank"}, :include => :firm_with_primary_key)
-    assert_not_nil citibank_result.instance_variable_get("@firm_with_primary_key")
+    assert citibank_result.association_cache.key?(:firm_with_primary_key)
   end
 
   def test_eager_loading_with_primary_key_as_symbol
     Firm.create("name" => "Apple")
     Client.create("name" => "Citibank", :firm_name => "Apple")
     citibank_result = Client.find(:first, :conditions => {:name => "Citibank"}, :include => :firm_with_primary_key_symbols)
-    assert_not_nil citibank_result.instance_variable_get("@firm_with_primary_key_symbols")
-  end
-
-  def test_no_unexpected_aliasing
-    first_firm = companies(:first_firm)
-    another_firm = companies(:another_firm)
-
-    citibank = Account.create("credit_limit" => 10)
-    citibank.firm = first_firm
-    original_proxy = citibank.firm
-    citibank.firm = another_firm
-
-    assert_equal first_firm.object_id, original_proxy.target.object_id
-    assert_equal another_firm.object_id, citibank.firm.target.object_id
+    assert citibank_result.association_cache.key?(:firm_with_primary_key_symbols)
   end
 
   def test_creating_the_belonging_object
@@ -133,6 +120,23 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal apple.name, client.firm_name
   end
 
+  def test_create!
+    client  = Client.create!(:name => "Jimmy")
+    account = client.create_account!(:credit_limit => 10)
+    assert_equal account, client.account
+    assert account.persisted?
+    client.save
+    client.reload
+    assert_equal account, client.account
+  end
+
+  def test_failing_create!
+    client  = Client.create!(:name => "Jimmy")
+    assert_raise(ActiveRecord::RecordInvalid) { client.create_account! }
+    assert_not_nil client.account
+    assert client.account.new_record?
+  end
+
   def test_natural_assignment_to_nil
     client = Client.find(3)
     client.firm = nil
@@ -159,6 +163,15 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_not_nil Company.find(3).firm_with_condition, "Microsoft should have a firm"
   end
 
+  def test_with_polymorphic_and_condition
+    sponsor = Sponsor.create
+    member = Member.create :name => "Bert"
+    sponsor.sponsorable = member
+
+    assert_equal member, sponsor.sponsorable
+    assert_nil sponsor.sponsorable_with_conditions
+  end
+
   def test_with_select
     assert_equal Company.find(2).firm_with_select.attributes.size, 1
     assert_equal Company.find(2, :include => :firm_with_select ).firm_with_select.attributes.size, 1
@@ -175,17 +188,6 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal 0, Topic.find(debate.id).send(:read_attribute, "replies_count"), "First reply deleted"
   end
 
-  def test_belongs_to_with_primary_key_counter
-    debate = Topic.create("title" => "debate")
-    assert_equal 0, debate.send(:read_attribute, "replies_count"), "No replies yet"
-
-    trash = debate.replies_with_primary_key.create("title" => "blah!", "content" => "world around!")
-    assert_equal 1, Topic.find(debate.id).send(:read_attribute, "replies_count"), "First reply created"
-
-    trash.destroy
-    assert_equal 0, Topic.find(debate.id).send(:read_attribute, "replies_count"), "First reply deleted"
-  end
-
   def test_belongs_to_counter_with_assigning_nil
     p = Post.find(1)
     c = Comment.find(1)
@@ -198,16 +200,23 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal 1, Post.find(p.id).comments.size
   end
 
-  def test_belongs_to_with_primary_key_counter_with_assigning_nil
-    debate = Topic.create("title" => "debate")
-    reply  = Reply.create("title" => "blah!", "content" => "world around!", "parent_title" => "debate")
+  def test_belongs_to_with_primary_key_counter
+    debate  = Topic.create("title" => "debate")
+    debate2 = Topic.create("title" => "debate2")
+    reply   = Reply.create("title" => "blah!", "content" => "world around!", "parent_title" => "debate")
 
-    assert_equal debate.title, reply.parent_title
-    assert_equal 1, Topic.find(debate.id).send(:read_attribute, "replies_count")
+    assert_equal 1, debate.reload.replies_count
+    assert_equal 0, debate2.reload.replies_count
+
+    reply.topic_with_primary_key = debate2
+
+    assert_equal 0, debate.reload.replies_count
+    assert_equal 1, debate2.reload.replies_count
 
     reply.topic_with_primary_key = nil
 
-    assert_equal 0, Topic.find(debate.id).send(:read_attribute, "replies_count")
+    assert_equal 0, debate.reload.replies_count
+    assert_equal 0, debate2.reload.replies_count
   end
 
   def test_belongs_to_counter_with_reassigning
@@ -311,13 +320,21 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_equal Firm.find(:first, :order => "id"), c.firm_with_basic_id
   end
 
-  def test_forgetting_the_load_when_foreign_key_enters_late
-    c = Client.new
-    assert_nil c.firm_with_basic_id
+  def test_setting_foreign_key_after_nil_target_loaded
+    client = Client.new
+    client.firm_with_basic_id
+    client.firm_id = 1
 
-    c.firm_id = 1
-    # sometimes tests on Oracle fail if ORDER BY is not provided therefore add always :order with :first
-    assert_equal Firm.find(:first, :order => "id"), c.firm_with_basic_id
+    assert_equal companies(:first_firm), client.firm_with_basic_id
+  end
+
+  def test_polymorphic_setting_foreign_key_after_nil_target_loaded
+    sponsor = Sponsor.new
+    sponsor.sponsorable
+    sponsor.sponsorable_id = 1
+    sponsor.sponsorable_type = "Member"
+
+    assert_equal members(:groucho), sponsor.sponsorable
   end
 
   def test_field_name_same_as_foreign_key
@@ -419,6 +436,18 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_nil sponsor.sponsorable_id
   end
 
+  def test_assignment_updates_foreign_id_field_for_new_and_saved_records
+    client = Client.new
+    saved_firm = Firm.create :name => "Saved"
+    new_firm = Firm.new
+
+    client.firm = saved_firm
+    assert_equal saved_firm.id, client.client_of
+
+    client.firm = new_firm
+    assert_nil client.client_of
+  end
+
   def test_polymorphic_assignment_with_primary_key_updates_foreign_id_field_for_new_and_saved_records
     essay = Essay.new
     saved_writer = Author.create(:name => "David")
@@ -488,39 +517,116 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_reassigning_the_parent_id_updates_the_object
-    original_parent = Firm.create! :name => "original"
-    updated_parent = Firm.create! :name => "updated"
+    client = companies(:second_client)
 
-    client = Client.new("client_of" => original_parent.id)
-    assert_equal original_parent, client.firm
-    assert_equal original_parent, client.firm_with_condition
-    assert_equal original_parent, client.firm_with_other_name
+    client.firm
+    client.firm_with_condition
+    firm_proxy                = client.send(:association_instance_get, :firm)
+    firm_with_condition_proxy = client.send(:association_instance_get, :firm_with_condition)
 
-    client.client_of = updated_parent.id
-    assert_equal updated_parent, client.firm
-    assert_equal updated_parent, client.firm_with_condition
-    assert_equal updated_parent, client.firm_with_other_name
+    assert !firm_proxy.stale_target?
+    assert !firm_with_condition_proxy.stale_target?
+    assert_equal companies(:first_firm), client.firm
+    assert_equal companies(:first_firm), client.firm_with_condition
+
+    client.client_of = companies(:another_firm).id
+
+    assert firm_proxy.stale_target?
+    assert firm_with_condition_proxy.stale_target?
+    assert_equal companies(:another_firm), client.firm
+    assert_equal companies(:another_firm), client.firm_with_condition
   end
 
   def test_polymorphic_reassignment_of_associated_id_updates_the_object
-    member1 = Member.create!
-    member2 = Member.create!
+    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
+
+    sponsor.sponsorable
+    proxy = sponsor.send(:association_instance_get, :sponsorable)
+
+    assert !proxy.stale_target?
+    assert_equal members(:groucho), sponsor.sponsorable
 
-    sponsor = Sponsor.new("sponsorable_type" => "Member", "sponsorable_id" => member1.id)
-    assert_equal member1, sponsor.sponsorable
+    sponsor.sponsorable_id = members(:some_other_guy).id
 
-    sponsor.sponsorable_id = member2.id
-    assert_equal member2, sponsor.sponsorable
+    assert proxy.stale_target?
+    assert_equal members(:some_other_guy), sponsor.sponsorable
   end
 
   def test_polymorphic_reassignment_of_associated_type_updates_the_object
-    member1 = Member.create!
+    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
+
+    sponsor.sponsorable
+    proxy = sponsor.send(:association_instance_get, :sponsorable)
+
+    assert !proxy.stale_target?
+    assert_equal members(:groucho), sponsor.sponsorable
+
+    sponsor.sponsorable_type = 'Firm'
+
+    assert proxy.stale_target?
+    assert_equal companies(:first_firm), sponsor.sponsorable
+  end
+
+  def test_reloading_association_with_key_change
+    client = companies(:second_client)
+    firm = client.firm # note this is a proxy object
+
+    client.firm = companies(:another_firm)
+    assert_equal companies(:another_firm), firm.reload
+
+    client.client_of = companies(:first_firm).id
+    assert_equal companies(:first_firm), firm.reload
+  end
+
+  def test_polymorphic_counter_cache
+    tagging = taggings(:welcome_general)
+    post    = posts(:welcome)
+    comment = comments(:greetings)
+
+    assert_difference 'post.reload.taggings_count', -1 do
+      assert_difference 'comment.reload.taggings_count', +1 do
+        tagging.taggable = comment
+      end
+    end
+  end
+
+  def test_polymorphic_with_custom_foreign_type
+    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
+    groucho = members(:groucho)
+    other   = members(:some_other_guy)
+
+    assert_equal groucho, sponsor.sponsorable
+    assert_equal groucho, sponsor.thing
+
+    sponsor.thing = other
+
+    assert_equal other, sponsor.sponsorable
+    assert_equal other, sponsor.thing
 
-    sponsor = Sponsor.new("sponsorable_type" => "Member", "sponsorable_id" => member1.id)
-    assert_equal member1, sponsor.sponsorable
+    sponsor.sponsorable = groucho
 
-    sponsor.sponsorable_type = "Firm"
-    assert_not_equal member1, sponsor.sponsorable
+    assert_equal groucho, sponsor.sponsorable
+    assert_equal groucho, sponsor.thing
   end
 
+  def test_build_with_conditions
+    client = companies(:second_client)
+    firm   = client.build_bob_firm
+
+    assert_equal "Bob", firm.name
+  end
+
+  def test_create_with_conditions
+    client = companies(:second_client)
+    firm   = client.create_bob_firm
+
+    assert_equal "Bob", firm.name
+  end
+
+  def test_create_bang_with_conditions
+    client = companies(:second_client)
+    firm   = client.create_bob_firm!
+
+    assert_equal "Bob", firm.name
+  end
 end
diff --git a/activerecord/test/cases/associations/callbacks_test.rb b/activerecord/test/cases/associations/callbacks_test.rb
index 6a30e2905b..2d0d4541b4 100644
--- a/activerecord/test/cases/associations/callbacks_test.rb
+++ b/activerecord/test/cases/associations/callbacks_test.rb
@@ -3,6 +3,7 @@ require 'models/post'
 require 'models/author'
 require 'models/project'
 require 'models/developer'
+require 'models/company'
 
 class AssociationCallbacksTest < ActiveRecord::TestCase
   fixtures :posts, :authors, :projects, :developers
@@ -81,6 +82,14 @@ class AssociationCallbacksTest < ActiveRecord::TestCase
     assert_equal callback_log, jack.post_log
   end
 
+  def test_has_many_callbacks_for_destroy_on_parent
+    firm = Firm.create! :name => "Firm"
+    client = firm.clients.create! :name => "Client"
+    firm.destroy
+
+    assert_equal ["before_remove#{client.id}", "after_remove#{client.id}"], firm.log
+  end
+
   def test_has_and_belongs_to_many_add_callback
     david = developers(:david)
     ar = projects(:active_record)
diff --git a/activerecord/test/cases/associations/eager_load_nested_include_test.rb b/activerecord/test/cases/associations/eager_load_nested_include_test.rb
index c7671a8c22..2cf9f89c3c 100644
--- a/activerecord/test/cases/associations/eager_load_nested_include_test.rb
+++ b/activerecord/test/cases/associations/eager_load_nested_include_test.rb
@@ -1,9 +1,11 @@
 require 'cases/helper'
 require 'models/post'
+require 'models/tag'
 require 'models/author'
 require 'models/comment'
 require 'models/category'
 require 'models/categorization'
+require 'models/tagging'
 require 'active_support/core_ext/array/random_access'
 
 module Remembered
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index c064731859..650bb15b55 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -21,12 +21,13 @@ require 'models/member'
 require 'models/membership'
 require 'models/club'
 require 'models/categorization'
+require 'models/sponsor'
 
 class EagerAssociationTest < ActiveRecord::TestCase
   fixtures :posts, :comments, :authors, :author_addresses, :categories, :categories_posts,
             :companies, :accounts, :tags, :taggings, :people, :readers, :categorizations,
             :owners, :pets, :author_favorites, :jobs, :references, :subscribers, :subscriptions, :books,
-            :developers, :projects, :developers_projects, :members, :memberships, :clubs
+            :developers, :projects, :developers_projects, :members, :memberships, :clubs, :sponsors
 
   def setup
     # preheat table existence caches
@@ -211,6 +212,15 @@ class EagerAssociationTest < ActiveRecord::TestCase
     end
   end
 
+  def test_finding_with_includes_on_null_belongs_to_polymorphic_association
+    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
+    sponsor.update_attributes!(:sponsorable => nil)
+    sponsor = assert_queries(1) { Sponsor.find(sponsor.id, :include => :sponsorable) }
+    assert_no_queries do
+      assert_equal nil, sponsor.sponsorable
+    end
+  end
+
   def test_loading_from_an_association
     posts = authors(:david).posts.find(:all, :include => :comments, :order => "posts.id")
     assert_equal 2, posts.first.comments.size
@@ -659,7 +669,11 @@ class EagerAssociationTest < ActiveRecord::TestCase
   end
 
   def test_preload_with_interpolation
-    assert_equal [comments(:greetings)], Post.find(posts(:welcome).id, :include => :comments_with_interpolated_conditions).comments_with_interpolated_conditions
+    post = Post.includes(:comments_with_interpolated_conditions).find(posts(:welcome).id)
+    assert_equal [comments(:greetings)], post.comments_with_interpolated_conditions
+
+    post = Post.joins(:comments_with_interpolated_conditions).find(posts(:welcome).id)
+    assert_equal [comments(:greetings)], post.comments_with_interpolated_conditions
   end
 
   def test_polymorphic_type_condition
@@ -845,6 +859,8 @@ class EagerAssociationTest < ActiveRecord::TestCase
   end
 
   def test_eager_loading_with_conditions_on_join_model_preloads
+    Author.columns
+
     authors = assert_queries(2) do
       Author.find(:all, :include => :author_address, :joins => :comments, :conditions => "posts.title like 'Welcome%'")
     end
@@ -890,26 +906,40 @@ class EagerAssociationTest < ActiveRecord::TestCase
   end
 
   def test_preload_has_one_using_primary_key
-    expected = Firm.find(:first).account_using_primary_key
-    firm = Firm.find :first, :include => :account_using_primary_key
+    expected = accounts(:signals37)
+    firm = Firm.find :first, :include => :account_using_primary_key, :order => 'companies.id'
     assert_no_queries do
       assert_equal expected, firm.account_using_primary_key
     end
   end
 
   def test_include_has_one_using_primary_key
-    expected = Firm.find(1).account_using_primary_key
+    expected = accounts(:signals37)
     firm = Firm.find(:all, :include => :account_using_primary_key, :order => 'accounts.id').detect {|f| f.id == 1}
     assert_no_queries do
       assert_equal expected, firm.account_using_primary_key
     end
   end
 
-  def test_preloading_empty_polymorphic_parent
+  def test_preloading_empty_belongs_to
+    c = Client.create!(:name => 'Foo', :client_of => Company.maximum(:id) + 1)
+
+    client = assert_queries(2) { Client.preload(:firm).find(c.id) }
+    assert_no_queries { assert_nil client.firm }
+  end
+
+  def test_preloading_empty_belongs_to_polymorphic
     t = Tagging.create!(:taggable_type => 'Post', :taggable_id => Post.maximum(:id) + 1, :tag => tags(:general))
 
-    assert_queries(2) { @tagging = Tagging.preload(:taggable).find(t.id) }
-    assert_no_queries { assert ! @tagging.taggable }
+    tagging = assert_queries(1) { Tagging.preload(:taggable).find(t.id) }
+    assert_no_queries { assert_nil tagging.taggable }
+  end
+
+  def test_preloading_through_empty_belongs_to
+    c = Client.create!(:name => 'Foo', :client_of => Company.maximum(:id) + 1)
+
+    client = assert_queries(2) { Client.preload(:accounts).find(c.id) }
+    assert_no_queries { assert client.accounts.empty? }
   end
 
   def test_preloading_has_many_through_with_uniq
@@ -917,4 +947,14 @@ class EagerAssociationTest < ActiveRecord::TestCase
     assert_equal 1, mary.unique_categorized_posts.length
     assert_equal 1, mary.unique_categorized_post_ids.length
   end
+
+  def test_preloading_polymorphic_with_custom_foreign_type
+    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
+    groucho = members(:groucho)
+
+    sponsor = assert_queries(2) {
+      Sponsor.includes(:thing).where(:id => sponsor.id).first
+    }
+    assert_no_queries { assert_equal groucho, sponsor.thing }
+  end
 end
diff --git a/activerecord/test/cases/associations/extension_test.rb b/activerecord/test/cases/associations/extension_test.rb
index efaab8569e..e1f5b16eca 100644
--- a/activerecord/test/cases/associations/extension_test.rb
+++ b/activerecord/test/cases/associations/extension_test.rb
@@ -29,6 +29,11 @@ class AssociationsExtensionsTest < ActiveRecord::TestCase
     assert_equal projects(:action_controller), developers(:david).projects_extended_by_name_and_block.find_most_recent
     assert_equal projects(:active_record), developers(:david).projects_extended_by_name_and_block.find_least_recent
   end
+  
+  def test_extension_with_scopes
+    assert_equal comments(:greetings), posts(:welcome).comments.offset(1).find_most_recent
+    assert_equal comments(:greetings), posts(:welcome).comments.not_again.find_most_recent
+  end
 
   def test_marshalling_extensions
     david = developers(:david)
diff --git a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
index 705550216c..dc382c3007 100644
--- a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
@@ -72,7 +72,7 @@ class DeveloperWithCounterSQL < ActiveRecord::Base
     :join_table => "developers_projects",
     :association_foreign_key => "project_id",
     :foreign_key => "developer_id",
-    :counter_sql => 'SELECT COUNT(*) AS count_all FROM projects INNER JOIN developers_projects ON projects.id = developers_projects.project_id WHERE developers_projects.developer_id =#{id}'
+    :counter_sql => proc { "SELECT COUNT(*) AS count_all FROM projects INNER JOIN developers_projects ON projects.id = developers_projects.project_id WHERE developers_projects.developer_id =#{id}" }
 end
 
 class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
@@ -101,38 +101,6 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 't1', record[1]
   end
 
-  def test_should_record_timestamp_for_join_table
-    setup_data_for_habtm_case
-
-    con = ActiveRecord::Base.connection
-    sql = 'select * from countries_treaties'
-    record = con.select_rows(sql).last
-    assert_not_nil record[2]
-    assert_not_nil record[3]
-    if current_adapter?(:Mysql2Adapter, :OracleAdapter)
-      assert_match %r{\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}}, record[2].to_s(:db)
-      assert_match %r{\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}}, record[3].to_s(:db)
-    else
-      assert_match %r{\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}}, record[2]
-      assert_match %r{\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}}, record[3]
-    end
-  end
-
-  def test_should_record_timestamp_for_join_table_only_if_timestamp_should_be_recorded
-    begin
-      Treaty.record_timestamps = false
-      setup_data_for_habtm_case
-
-      con = ActiveRecord::Base.connection
-      sql = 'select * from countries_treaties'
-      record = con.select_rows(sql).last
-      assert_nil record[2]
-      assert_nil record[3]
-    ensure
-      Treaty.record_timestamps = true
-    end
-  end
-
   def test_has_and_belongs_to_many
     david = Developer.find(1)
 
@@ -218,34 +186,6 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 2, aredridel.projects(true).size
   end
 
-  def test_adding_uses_default_values_on_join_table
-    ac = projects(:action_controller)
-    assert !developers(:jamis).projects.include?(ac)
-    developers(:jamis).projects << ac
-
-    assert developers(:jamis, :reload).projects.include?(ac)
-    project = developers(:jamis).projects.detect { |p| p == ac }
-    assert_equal 1, project.access_level.to_i
-  end
-
-  def test_habtm_attribute_access_and_respond_to
-    project = developers(:jamis).projects[0]
-    assert project.has_attribute?("name")
-    assert project.has_attribute?("joined_on")
-    assert project.has_attribute?("access_level")
-    assert project.respond_to?("name")
-    assert project.respond_to?("name=")
-    assert project.respond_to?("name?")
-    assert project.respond_to?("joined_on")
-    # given that the 'join attribute' won't be persisted, I don't
-    # think we should define the mutators
-    #assert project.respond_to?("joined_on=")
-    assert project.respond_to?("joined_on?")
-    assert project.respond_to?("access_level")
-    #assert project.respond_to?("access_level=")
-    assert project.respond_to?("access_level?")
-  end
-
   def test_habtm_adding_before_save
     no_of_devels = Developer.count
     no_of_projects = Project.count
@@ -425,38 +365,41 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
   def test_removing_associations_on_destroy
     david = DeveloperWithBeforeDestroyRaise.find(1)
     assert !david.projects.empty?
-    assert_raise(RuntimeError) { david.destroy }
+    david.destroy
     assert david.projects.empty?
     assert DeveloperWithBeforeDestroyRaise.connection.select_all("SELECT * FROM developers_projects WHERE developer_id = 1").empty?
   end
 
-  def test_additional_columns_from_join_table
-    assert_date_from_db Date.new(2004, 10, 10), Developer.find(1).projects.first.joined_on.to_date
-  end
-
   def test_destroying
     david = Developer.find(1)
-    active_record = Project.find(1)
+    project = Project.find(1)
     david.projects.reload
     assert_equal 2, david.projects.size
-    assert_equal 3, active_record.developers.size
+    assert_equal 3, project.developers.size
 
-    assert_difference "Project.count", -1 do
-      david.projects.destroy(active_record)
+    assert_no_difference "Project.count" do
+      david.projects.destroy(project)
     end
 
+    join_records = Developer.connection.select_all("SELECT * FROM developers_projects WHERE developer_id = #{david.id} AND project_id = #{project.id}")
+    assert join_records.empty?
+
     assert_equal 1, david.reload.projects.size
     assert_equal 1, david.projects(true).size
   end
 
-  def test_destroying_array
+  def test_destroying_many
     david = Developer.find(1)
     david.projects.reload
+    projects = Project.all
 
-    assert_difference "Project.count", -Project.count do
-      david.projects.destroy(Project.find(:all))
+    assert_no_difference "Project.count" do
+      david.projects.destroy(*projects)
     end
 
+    join_records = Developer.connection.select_all("SELECT * FROM developers_projects WHERE developer_id = #{david.id}")
+    assert join_records.empty?
+
     assert_equal 0, david.reload.projects.size
     assert_equal 0, david.projects(true).size
   end
@@ -465,7 +408,14 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
     david = Developer.find(1)
     david.projects.reload
     assert !david.projects.empty?
-    david.projects.destroy_all
+
+    assert_no_difference "Project.count" do
+      david.projects.destroy_all
+    end
+
+    join_records = Developer.connection.select_all("SELECT * FROM developers_projects WHERE developer_id = #{david.id}")
+    assert join_records.empty?
+
     assert david.projects.empty?
     assert david.projects(true).empty?
   end
@@ -675,25 +625,6 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
     assert_respond_to categories(:technology).select_testing_posts.find(:first), :correctness_marker
   end
 
-  def test_updating_attributes_on_rich_associations
-    david = projects(:action_controller).developers.first
-    david.name = "DHH"
-    assert_raise(ActiveRecord::ReadOnlyRecord) { david.save! }
-  end
-
-  def test_updating_attributes_on_rich_associations_with_limited_find_from_reflection
-    david = projects(:action_controller).selected_developers.first
-    david.name = "DHH"
-    assert_nothing_raised { david.save! }
-  end
-
-
-  def test_updating_attributes_on_rich_associations_with_limited_find
-    david = projects(:action_controller).developers.find(:all, :select => "developers.*").first
-    david.name = "DHH"
-    assert david.save!
-  end
-
   def test_join_table_alias
     assert_equal 3, Developer.find(:all, :include => {:projects => :developers}, :conditions => 'developers_projects_join.joined_on IS NOT NULL').size
   end
@@ -840,10 +771,13 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
     david = Developer.find(1)
     # clear cache possibly created by other tests
     david.projects.reset_column_information
-    assert_queries(0) { david.projects.columns; david.projects.columns }
-    # and again to verify that reset_column_information clears the cache correctly
+
+    # One query for columns, one for primary key
+    assert_queries(2) { david.projects.columns; david.projects.columns }
+
+    ## and again to verify that reset_column_information clears the cache correctly
     david.projects.reset_column_information
-    assert_queries(0) { david.projects.columns; david.projects.columns }
+    assert_queries(2) { david.projects.columns; david.projects.columns }
   end
 
   def test_attributes_are_being_set_when_initialized_from_habm_association_with_where_clause
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index fb772bb8e6..ad774eb9ce 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -43,7 +43,7 @@ end
 class HasManyAssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :categories, :companies, :developers, :projects,
            :developers_projects, :topics, :authors, :comments,
-           :people, :posts, :readers, :taggings
+           :people, :posts, :readers, :taggings, :cars
 
   def setup
     Client.destroyed_client_ids.clear
@@ -66,14 +66,36 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal 'exotic', bulb.name
   end
 
+  # When creating objects on the association, we must not do it within a scope (even though it
+  # would be convenient), because this would cause that scope to be applied to any callbacks etc.
+  def test_build_and_create_should_not_happen_within_scope
+    car = cars(:honda)
+    original_scoped_methods = Bulb.scoped_methods
+
+    bulb = car.bulbs.build
+    assert_equal original_scoped_methods, bulb.scoped_methods_after_initialize
+
+    bulb = car.bulbs.create
+    assert_equal original_scoped_methods, bulb.scoped_methods_after_initialize
+
+    bulb = car.bulbs.create!
+    assert_equal original_scoped_methods, bulb.scoped_methods_after_initialize
+  end
+
   def test_no_sql_should_be_fired_if_association_already_loaded
     Car.create(:name => 'honda')
     bulbs = Car.first.bulbs
     bulbs.inspect # to load all instances of bulbs
+
     assert_no_queries do
       bulbs.first()
       bulbs.first({})
     end
+
+    assert_no_queries do
+      bulbs.last()
+      bulbs.last({})
+    end
   end
 
   def test_create_resets_cached_counters
@@ -257,7 +279,6 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
 
   def test_counting_using_finder_sql
     assert_equal 2, Firm.find(4).clients_using_sql.count
-    assert_equal 2, Firm.find(4).clients_using_multiline_sql.count
   end
 
   def test_belongs_to_sanity
@@ -608,7 +629,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal topic.replies.to_a.size, topic.replies_count
   end
 
-  def test_deleting_updates_counter_cache_without_dependent_destroy
+  def test_deleting_updates_counter_cache_without_dependent_option
     post = posts(:welcome)
 
     assert_difference "post.reload.taggings_count", -1 do
@@ -616,6 +637,24 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_deleting_updates_counter_cache_with_dependent_delete_all
+    post = posts(:welcome)
+    post.update_attribute(:taggings_with_delete_all_count, post.taggings_count)
+
+    assert_difference "post.reload.taggings_with_delete_all_count", -1 do
+      post.taggings_with_delete_all.delete(post.taggings_with_delete_all.first)
+    end
+  end
+
+  def test_deleting_updates_counter_cache_with_dependent_destroy
+    post = posts(:welcome)
+    post.update_attribute(:taggings_with_destroy_count, post.taggings_count)
+
+    assert_difference "post.reload.taggings_with_destroy_count", -1 do
+      post.taggings_with_destroy.delete(post.taggings_with_destroy.first)
+    end
+  end
+
   def test_deleting_a_collection
     force_signal37_to_load_all_clients_of_firm
     companies(:first_firm).clients_of_firm.create("name" => "Another Client")
@@ -628,8 +667,10 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   def test_delete_all
     force_signal37_to_load_all_clients_of_firm
     companies(:first_firm).clients_of_firm.create("name" => "Another Client")
-    assert_equal 2, companies(:first_firm).clients_of_firm.size
-    companies(:first_firm).clients_of_firm.delete_all
+    clients = companies(:first_firm).clients_of_firm.to_a
+    assert_equal 2, clients.count
+    deleted = companies(:first_firm).clients_of_firm.delete_all
+    assert_equal clients.sort_by(&:id), deleted.sort_by(&:id)
     assert_equal 0, companies(:first_firm).clients_of_firm.size
     assert_equal 0, companies(:first_firm).clients_of_firm(true).size
   end
@@ -649,11 +690,12 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     client_id = firm.clients_of_firm.first.id
     assert_equal 1, firm.clients_of_firm.size
 
-    firm.clients_of_firm.clear
+    cleared = firm.clients_of_firm.clear
 
     assert_equal 0, firm.clients_of_firm.size
     assert_equal 0, firm.clients_of_firm(true).size
     assert_equal [], Client.destroyed_client_ids[firm.id]
+    assert_equal firm.clients_of_firm.object_id, cleared.object_id
 
     # Should not be destroyed since the association is not dependent.
     assert_nothing_raised do
@@ -664,9 +706,9 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   def test_clearing_updates_counter_cache
     topic = Topic.first
 
-    topic.replies.clear
-    topic.reload
-    assert_equal 0, topic.replies_count
+    assert_difference 'topic.reload.replies_count', -1 do
+      topic.replies.clear
+    end
   end
 
   def test_clearing_a_dependent_association_collection
@@ -963,6 +1005,19 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert !firm.clients.include?(:first_client)
   end
 
+  def test_replace_failure
+    firm = companies(:first_firm)
+    account = Account.new
+    orig_accounts = firm.accounts.to_a
+
+    assert !account.valid?
+    assert !orig_accounts.empty?
+    assert_raise ActiveRecord::RecordNotSaved do
+      firm.accounts = [account]
+    end
+    assert_equal orig_accounts, firm.accounts
+  end
+
   def test_get_ids
     assert_equal [companies(:first_client).id, companies(:second_client).id], companies(:first_firm).client_ids
   end
@@ -1302,4 +1357,11 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal reply.id, first.id
     assert_equal true, first.approved?
   end
+
+  def test_to_a_should_dup_target
+    ary    = topics(:first).replies.to_a
+    target = topics(:first).replies.target
+
+    assert_not_equal target.object_id, ary.object_id
+  end
 end
diff --git a/activerecord/test/cases/associations/has_many_through_associations_test.rb b/activerecord/test/cases/associations/has_many_through_associations_test.rb
index 77bc369ecc..73b1d6c500 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -19,10 +19,14 @@ require 'models/book'
 require 'models/subscription'
 require 'models/categorization'
 require 'models/category'
+require 'models/essay'
+require 'models/member'
+require 'models/membership'
+require 'models/club'
 
 class HasManyThroughAssociationsTest < ActiveRecord::TestCase
-  fixtures :posts, :readers, :people, :comments, :authors,
-           :owners, :pets, :toys, :jobs, :references, :companies,
+  fixtures :posts, :readers, :people, :comments, :authors, :categories, :taggings, :tags,
+           :owners, :pets, :toys, :jobs, :references, :companies, :members, :author_addresses,
            :subscribers, :books, :subscriptions, :developers, :categorizations
 
   # Dummies to force column loads so query counts are clean.
@@ -31,6 +35,13 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     Reader.create :person_id => 0, :post_id => 0
   end
 
+  def test_include?
+    person = Person.new
+    post = Post.new
+    person.posts << post
+    assert person.posts.include?(post)
+  end
+
   def test_associate_existing
     assert_queries(2) { posts(:thinking); people(:david) }
 
@@ -45,6 +56,16 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert posts(:thinking).reload.people(true).include?(people(:david))
   end
 
+  def test_associate_existing_record_twice_should_add_to_target_twice
+    post   = posts(:thinking)
+    person = people(:david)
+
+    assert_difference 'post.people.to_a.count', 2 do
+      post.people << person
+      post.people << person
+    end
+  end
+
   def test_associating_new
     assert_queries(1) { posts(:thinking) }
     new_person = nil # so block binding catches it
@@ -107,8 +128,10 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_destroy_association
-    assert_difference ["Person.count", "Reader.count"], -1 do
-      posts(:welcome).people.destroy(people(:michael))
+    assert_no_difference "Person.count" do
+      assert_difference "Reader.count", -1 do
+        posts(:welcome).people.destroy(people(:michael))
+      end
     end
 
     assert posts(:welcome).reload.people.empty?
@@ -116,8 +139,10 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_destroy_all
-    assert_difference ["Person.count", "Reader.count"], -1 do
-      posts(:welcome).people.destroy_all
+    assert_no_difference "Person.count" do
+      assert_difference "Reader.count", -1 do
+        posts(:welcome).people.destroy_all
+      end
     end
 
     assert posts(:welcome).reload.people.empty?
@@ -130,6 +155,137 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_delete_through_belongs_to_with_dependent_nullify
+    Reference.make_comments = true
+
+    person    = people(:michael)
+    job       = jobs(:magician)
+    reference = Reference.where(:job_id => job.id, :person_id => person.id).first
+
+    assert_no_difference ['Job.count', 'Reference.count'] do
+      assert_difference 'person.jobs.count', -1 do
+        person.jobs_with_dependent_nullify.delete(job)
+      end
+    end
+
+    assert_equal nil, reference.reload.job_id
+  ensure
+    Reference.make_comments = false
+  end
+
+  def test_delete_through_belongs_to_with_dependent_delete_all
+    Reference.make_comments = true
+
+    person = people(:michael)
+    job    = jobs(:magician)
+
+    # Make sure we're not deleting everything
+    assert person.jobs.count >= 2
+
+    assert_no_difference 'Job.count' do
+      assert_difference ['person.jobs.count', 'Reference.count'], -1 do
+        person.jobs_with_dependent_delete_all.delete(job)
+      end
+    end
+
+    # Check that the destroy callback on Reference did not run
+    assert_equal nil, person.reload.comments
+  ensure
+    Reference.make_comments = false
+  end
+
+  def test_delete_through_belongs_to_with_dependent_destroy
+    Reference.make_comments = true
+
+    person = people(:michael)
+    job    = jobs(:magician)
+
+    # Make sure we're not deleting everything
+    assert person.jobs.count >= 2
+
+    assert_no_difference 'Job.count' do
+      assert_difference ['person.jobs.count', 'Reference.count'], -1 do
+        person.jobs_with_dependent_destroy.delete(job)
+      end
+    end
+
+    # Check that the destroy callback on Reference ran
+    assert_equal "Reference destroyed", person.reload.comments
+  ensure
+    Reference.make_comments = false
+  end
+
+  def test_belongs_to_with_dependent_destroy
+    person = PersonWithDependentDestroyJobs.find(1)
+
+    # Create a reference which is not linked to a job. This should not be destroyed.
+    person.references.create!
+
+    assert_no_difference 'Job.count' do
+      assert_difference 'Reference.count', -person.jobs.count do
+        person.destroy
+      end
+    end
+  end
+
+  def test_belongs_to_with_dependent_delete_all
+    person = PersonWithDependentDeleteAllJobs.find(1)
+
+    # Create a reference which is not linked to a job. This should not be destroyed.
+    person.references.create!
+
+    assert_no_difference 'Job.count' do
+      assert_difference 'Reference.count', -person.jobs.count do
+        person.destroy
+      end
+    end
+  end
+
+  def test_belongs_to_with_dependent_nullify
+    person = PersonWithDependentNullifyJobs.find(1)
+
+    references = person.references.to_a
+
+    assert_no_difference ['Reference.count', 'Job.count'] do
+      person.destroy
+    end
+
+    references.each do |reference|
+      assert_equal nil, reference.reload.job_id
+    end
+  end
+
+  def test_update_counter_caches_on_delete
+    post = posts(:welcome)
+    tag  = post.tags.create!(:name => 'doomed')
+
+    assert_difference ['post.reload.taggings_count', 'post.reload.tags_count'], -1 do
+      posts(:welcome).tags.delete(tag)
+    end
+  end
+
+  def test_update_counter_caches_on_delete_with_dependent_destroy
+    post = posts(:welcome)
+    tag  = post.tags.create!(:name => 'doomed')
+    post.update_attribute(:tags_with_destroy_count, post.tags.count)
+
+    assert_difference ['post.reload.taggings_count', 'post.reload.tags_with_destroy_count'], -1 do
+      posts(:welcome).tags_with_destroy.delete(tag)
+    end
+  end
+
+  def test_update_counter_caches_on_delete_with_dependent_nullify
+    post = posts(:welcome)
+    tag  = post.tags.create!(:name => 'doomed')
+    post.update_attribute(:tags_with_nullify_count, post.tags.count)
+
+    assert_no_difference 'post.reload.taggings_count' do
+      assert_difference 'post.reload.tags_with_nullify_count', -1 do
+        posts(:welcome).tags_with_nullify.delete(tag)
+      end
+    end
+  end
+
   def test_replace_association
     assert_queries(4){posts(:welcome);people(:david);people(:michael); posts(:welcome).people(true)}
 
@@ -324,12 +480,8 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal 2, people(:michael).jobs.size
   end
 
-  def test_get_ids_for_belongs_to_source
-    assert_sql(/DISTINCT/) { assert_equal [posts(:welcome).id, posts(:authorless).id].sort, people(:michael).post_ids.sort }
-  end
-
-  def test_get_ids_for_has_many_source
-    assert_equal [comments(:eager_other_comment1).id], authors(:mary).comment_ids
+  def test_get_ids
+    assert_equal [posts(:welcome).id, posts(:authorless).id].sort, people(:michael).post_ids.sort
   end
 
   def test_get_ids_for_loaded_associations
@@ -397,6 +549,34 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal people(:susan).agents.map(&:agents).flatten, people(:susan).agents_of_agents
   end
 
+  def test_associate_existing_with_nonstandard_primary_key_on_belongs_to
+    Categorization.create(:author => authors(:mary), :named_category_name => categories(:general).name)
+    assert_equal categories(:general), authors(:mary).named_categories.first
+  end
+
+  def test_collection_build_with_nonstandard_primary_key_on_belongs_to
+    author   = authors(:mary)
+    category = author.named_categories.build(:name => "Primary")
+    author.save
+    assert Categorization.exists?(:author_id => author.id, :named_category_name => category.name)
+    assert author.named_categories(true).include?(category)
+  end
+
+  def test_collection_create_with_nonstandard_primary_key_on_belongs_to
+    author   = authors(:mary)
+    category = author.named_categories.create(:name => "Primary")
+    assert Categorization.exists?(:author_id => author.id, :named_category_name => category.name)
+    assert author.named_categories(true).include?(category)
+  end
+
+  def test_collection_delete_with_nonstandard_primary_key_on_belongs_to
+    author   = authors(:mary)
+    category = author.named_categories.create(:name => "Primary")
+    author.named_categories.delete(category)
+    assert !Categorization.exists?(:author_id => author.id, :named_category_name => category.name)
+    assert author.named_categories(true).empty?
+  end
+
   def test_collection_singular_ids_getter_with_string_primary_keys
     book = books(:awdr)
     assert_equal 2, book.subscriber_ids.size
@@ -466,7 +646,7 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_has_many_through_with_default_scope_on_join_model
-    assert_equal posts(:welcome).comments, authors(:david).comments_on_first_posts
+    assert_equal posts(:welcome).comments.order('id').all, authors(:david).comments_on_first_posts
   end
 
   def test_create_has_many_through_with_default_scope_on_join_model
@@ -479,4 +659,63 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal 1, mary.unique_categorized_posts.length
     assert_equal 1, mary.unique_categorized_post_ids.length
   end
+
+  def test_joining_has_many_through_belongs_to
+    posts = Post.joins(:author_categorizations).
+                 where('categorizations.id' => categorizations(:mary_thinking_sti).id)
+
+    assert_equal [posts(:eager_other)], posts
+  end
+
+  def test_select_chosen_fields_only
+    author = authors(:david)
+    assert_equal ['body'], author.comments.select('comments.body').first.attributes.keys
+  end
+
+  def test_get_has_many_through_belongs_to_ids_with_conditions
+    assert_equal [categories(:general).id], authors(:mary).categories_like_general_ids
+  end
+
+  def test_count_has_many_through_with_named_scope
+    assert_equal 2, authors(:mary).categories.count
+    assert_equal 1, authors(:mary).categories.general.count
+  end
+
+  def test_has_many_through_belongs_to_should_update_when_the_through_foreign_key_changes
+    post = posts(:eager_other)
+
+    post.author_categorizations
+    proxy = post.send(:association_instance_get, :author_categorizations)
+
+    assert !proxy.stale_target?
+    assert_equal authors(:mary).categorizations.sort_by(&:id), post.author_categorizations.sort_by(&:id)
+
+    post.author_id = authors(:david).id
+
+    assert proxy.stale_target?
+    assert_equal authors(:david).categorizations.sort_by(&:id), post.author_categorizations.sort_by(&:id)
+  end
+
+  def test_create_with_conditions_hash_on_through_association
+    member = members(:groucho)
+    club   = member.clubs.create!
+
+    assert_equal true, club.reload.membership.favourite
+  end
+
+  def test_deleting_from_has_many_through_a_belongs_to_should_not_try_to_update_counter
+    post    = posts(:welcome)
+    address = author_addresses(:david_address)
+
+    assert post.author_addresses.include?(address)
+    post.author_addresses.delete(address)
+    assert post[:author_count].nil?
+  end
+
+  def test_interpolated_conditions
+    post = posts(:welcome)
+    assert !post.tags.empty?
+    assert_equal post.tags, post.interpolated_tags
+    assert_equal post.tags, post.interpolated_tags_2
+  end
 end
diff --git a/activerecord/test/cases/associations/has_one_associations_test.rb b/activerecord/test/cases/associations/has_one_associations_test.rb
index 64449df8f5..6b73a35905 100644
--- a/activerecord/test/cases/associations/has_one_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_associations_test.rb
@@ -2,9 +2,13 @@ require "cases/helper"
 require 'models/developer'
 require 'models/project'
 require 'models/company'
+require 'models/ship'
+require 'models/pirate'
+require 'models/bulb'
 
 class HasOneAssociationsTest < ActiveRecord::TestCase
-  fixtures :accounts, :companies, :developers, :projects, :developers_projects
+  self.use_transactional_fixtures = false unless supports_savepoints?
+  fixtures :accounts, :companies, :developers, :projects, :developers_projects, :ships, :pirates
 
   def setup
     Account.destroyed_account_ids.clear
@@ -91,18 +95,18 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
   def test_nullification_on_association_change
     firm = companies(:rails_core)
     old_account_id = firm.account.id
-    firm.account = Account.new
+    firm.account = Account.new(:credit_limit => 5)
     # account is dependent with nullify, therefore its firm_id should be nil
     assert_nil Account.find(old_account_id).firm_id
   end
 
   def test_association_change_calls_delete
-    companies(:first_firm).deletable_account = Account.new
+    companies(:first_firm).deletable_account = Account.new(:credit_limit => 5)
     assert_equal [], Account.destroyed_account_ids[companies(:first_firm).id]
   end
 
   def test_association_change_calls_destroy
-    companies(:first_firm).account = Account.new
+    companies(:first_firm).account = Account.new(:credit_limit => 5)
     assert_equal [companies(:first_firm).id], Account.destroyed_account_ids[companies(:first_firm).id]
   end
 
@@ -116,35 +120,6 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     assert_equal company.account, account
   end
 
-  def test_assignment_without_replacement
-    apple = Firm.create("name" => "Apple")
-    citibank = Account.create("credit_limit" => 10)
-    apple.account = citibank
-    assert_equal apple.id, citibank.firm_id
-
-    hsbc = apple.build_account({ :credit_limit => 20}, false)
-    assert_equal apple.id, hsbc.firm_id
-    hsbc.save
-    assert_equal apple.id, citibank.firm_id
-
-    nykredit = apple.create_account({ :credit_limit => 30}, false)
-    assert_equal apple.id, nykredit.firm_id
-    assert_equal apple.id, citibank.firm_id
-    assert_equal apple.id, hsbc.firm_id
-  end
-
-  def test_assignment_without_replacement_on_create
-    apple = Firm.create("name" => "Apple")
-    citibank = Account.create("credit_limit" => 10)
-    apple.account = citibank
-    assert_equal apple.id, citibank.firm_id
-
-    hsbc = apple.create_account({:credit_limit => 10}, false)
-    assert_equal apple.id, hsbc.firm_id
-    hsbc.save
-    assert_equal apple.id, citibank.firm_id
-  end
-
   def test_dependence
     num_accounts = Account.count
 
@@ -193,13 +168,18 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     assert_equal account, firm.account
   end
 
-  def test_build_association_twice_without_saving_affects_nothing
-    count_of_account = Account.count
-    firm = Firm.find(:first)
-    firm.build_account("credit_limit" => 1000)
-    firm.build_account("credit_limit" => 2000)
+  def test_build_and_create_should_not_happen_within_scope
+    pirate = pirates(:blackbeard)
+    original_scoped_methods = Bulb.scoped_methods.dup
+
+    bulb = pirate.build_bulb
+    assert_equal original_scoped_methods, bulb.scoped_methods_after_initialize
 
-    assert_equal count_of_account, Account.count
+    bulb = pirate.create_bulb
+    assert_equal original_scoped_methods, bulb.scoped_methods_after_initialize
+
+    bulb = pirate.create_bulb!
+    assert_equal original_scoped_methods, bulb.scoped_methods_after_initialize
   end
 
   def test_create_association
@@ -208,25 +188,32 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     assert_equal account, firm.reload.account
   end
 
-  def test_build
-    firm = Firm.new("name" => "GlobalMegaCorp")
-    firm.save
+  def test_create_association_with_bang
+    firm = Firm.create(:name => "GlobalMegaCorp")
+    account = firm.create_account!(:credit_limit => 1000)
+    assert_equal account, firm.reload.account
+  end
 
-    firm.account = account = Account.new("credit_limit" => 1000)
-    assert_equal account, firm.account
-    assert account.save
-    assert_equal account, firm.account
+  def test_create_association_with_bang_failing
+    firm = Firm.create(:name => "GlobalMegaCorp")
+    assert_raise ActiveRecord::RecordInvalid do
+      firm.create_account!
+    end
+    account = firm.account
+    assert_not_nil account
+    account.credit_limit = 5
+    account.save
+    assert_equal account, firm.reload.account
   end
 
-  def test_failing_build_association
+  def test_build
     firm = Firm.new("name" => "GlobalMegaCorp")
     firm.save
 
-    firm.account = account = Account.new
+    firm.account = account = Account.new("credit_limit" => 1000)
     assert_equal account, firm.account
-    assert !account.save
+    assert account.save
     assert_equal account, firm.account
-    assert_equal ["can't be empty"], account.errors["credit_limit"]
   end
 
   def test_create
@@ -330,4 +317,51 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     new_account = companies(:first_firm).build_account(:firm_name => 'Account')
     assert_equal new_account.firm_name, "Account"
   end
+
+  def test_creation_failure_without_dependent_option
+    pirate = pirates(:blackbeard)
+    orig_ship = pirate.ship.target
+
+    assert_equal ships(:black_pearl), orig_ship
+    new_ship = pirate.create_ship
+    assert_not_equal ships(:black_pearl), new_ship
+    assert_equal new_ship, pirate.ship
+    assert new_ship.new_record?
+    assert_nil orig_ship.pirate_id
+    assert !orig_ship.changed? # check it was saved
+  end
+
+  def test_creation_failure_with_dependent_option
+    pirate = pirates(:blackbeard).becomes(DestructivePirate)
+    orig_ship = pirate.dependent_ship.target
+
+    new_ship = pirate.create_dependent_ship
+    assert new_ship.new_record?
+    assert orig_ship.destroyed?
+  end
+
+  def test_replacement_failure_due_to_existing_record_should_raise_error
+    pirate = pirates(:blackbeard)
+    pirate.ship.name = nil
+
+    assert !pirate.ship.valid?
+    assert_raise(ActiveRecord::RecordNotSaved) do
+      pirate.ship = ships(:interceptor)
+    end
+    assert_equal ships(:black_pearl), pirate.ship
+    assert_equal pirate.id, pirate.ship.pirate_id
+  end
+
+  def test_replacement_failure_due_to_new_record_should_raise_error
+    pirate = pirates(:blackbeard)
+    new_ship = Ship.new
+
+    assert_raise(ActiveRecord::RecordNotSaved) do
+      pirate.ship = new_ship
+    end
+    assert_equal ships(:black_pearl), pirate.ship
+    assert_equal pirate.id, pirate.ship.pirate_id
+    assert_equal pirate.id, ships(:black_pearl).reload.pirate_id
+    assert_nil new_ship.pirate_id
+  end
 end
diff --git a/activerecord/test/cases/associations/has_one_through_associations_test.rb b/activerecord/test/cases/associations/has_one_through_associations_test.rb
index 93a4f498d0..fc1db4e34b 100644
--- a/activerecord/test/cases/associations/has_one_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_through_associations_test.rb
@@ -25,10 +25,6 @@ class HasOneThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal clubs(:boring_club), @member.club
   end
 
-  def test_has_one_through_with_has_many
-    assert_equal clubs(:moustache_club), @member.favourite_club
-  end
-
   def test_creating_association_creates_through_record
     new_member = Member.create(:name => "Chris")
     new_member.club = Club.create(:name => "LRUG")
@@ -88,6 +84,18 @@ class HasOneThroughAssociationsTest < ActiveRecord::TestCase
     assert_not_nil assert_no_queries {members[0].sponsor_club}
   end
 
+  def test_has_one_through_with_conditions_eager_loading
+    # conditions on the through table
+    assert_equal clubs(:moustache_club), Member.find(@member.id, :include => :favourite_club).favourite_club
+    memberships(:membership_of_favourite_club).update_attribute(:favourite, false)
+    assert_equal nil,                    Member.find(@member.id, :include => :favourite_club).favourite_club.reload
+
+    # conditions on the source table
+    assert_equal clubs(:moustache_club), Member.find(@member.id, :include => :hairy_club).hairy_club
+    clubs(:moustache_club).update_attribute(:name, "Association of Clean-Shaven Persons")
+    assert_equal nil,                    Member.find(@member.id, :include => :hairy_club).hairy_club.reload
+  end
+
   def test_has_one_through_polymorphic_with_source_type
     assert_equal members(:groucho), clubs(:moustache_club).sponsored_member
   end
@@ -189,7 +197,7 @@ class HasOneThroughAssociationsTest < ActiveRecord::TestCase
       MemberDetail.find(:all, :include => :member_type)
     end
     @new_detail = @member_details[0]
-    assert @new_detail.loaded_member_type?
+    assert @new_detail.send(:association_proxy, :member_type).loaded?
     assert_not_nil assert_no_queries { @new_detail.member_type }
   end
 
@@ -235,6 +243,49 @@ class HasOneThroughAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_has_one_through_with_default_scope_on_join_model
-    assert_equal posts(:welcome).comments.first, authors(:david).comment_on_first_posts
+    assert_equal posts(:welcome).comments.order('id').first, authors(:david).comment_on_first_post
+  end
+
+  def test_has_one_through_many_raises_exception
+    assert_raise(ActiveRecord::HasOneThroughCantAssociateThroughCollection) do
+      members(:groucho).club_through_many
+    end
+  end
+
+  def test_has_one_through_belongs_to_should_update_when_the_through_foreign_key_changes
+    minivan = minivans(:cool_first)
+
+    minivan.dashboard
+    proxy = minivan.send(:association_instance_get, :dashboard)
+
+    assert !proxy.stale_target?
+    assert_equal dashboards(:cool_first), minivan.dashboard
+
+    minivan.speedometer_id = speedometers(:second).id
+
+    assert proxy.stale_target?
+    assert_equal dashboards(:second), minivan.dashboard
+  end
+
+  def test_has_one_through_belongs_to_setting_belongs_to_foreign_key_after_nil_target_loaded
+    minivan = Minivan.new
+
+    minivan.dashboard
+    proxy = minivan.send(:association_instance_get, :dashboard)
+
+    minivan.speedometer_id = speedometers(:second).id
+
+    assert proxy.stale_target?
+    assert_equal dashboards(:second), minivan.dashboard
+  end
+
+  def test_assigning_has_one_through_belongs_to_with_new_record_owner
+    minivan   = Minivan.new
+    dashboard = dashboards(:cool_first)
+
+    minivan.dashboard = dashboard
+
+    assert_equal dashboard, minivan.dashboard
+    assert_equal dashboard, minivan.speedometer.dashboard
   end
 end
diff --git a/activerecord/test/cases/associations/inner_join_association_test.rb b/activerecord/test/cases/associations/inner_join_association_test.rb
index da2a81e98a..e2228228a3 100644
--- a/activerecord/test/cases/associations/inner_join_association_test.rb
+++ b/activerecord/test/cases/associations/inner_join_association_test.rb
@@ -4,6 +4,7 @@ require 'models/comment'
 require 'models/author'
 require 'models/category'
 require 'models/categorization'
+require 'models/person'
 require 'models/tagging'
 require 'models/tag'
 
@@ -16,6 +17,13 @@ class InnerJoinAssociationTest < ActiveRecord::TestCase
     assert_equal authors(:david), result.first
   end
 
+  def test_construct_finder_sql_does_not_table_name_collide_on_duplicate_associations
+    assert_nothing_raised do
+      sql = Person.joins(:agents => {:agents => :agents}).joins(:agents => {:agents => {:primary_contact => :agents}}).to_sql
+      assert_match(/agents_people_4/i, sql)
+    end
+  end
+
   def test_construct_finder_sql_ignores_empty_joins_hash
     sql = Author.joins({}).to_sql
     assert_no_match(/JOIN/i, sql)
diff --git a/activerecord/test/cases/associations/inverse_associations_test.rb b/activerecord/test/cases/associations/inverse_associations_test.rb
index 0491b2d1fa..e9a57a00a0 100644
--- a/activerecord/test/cases/associations/inverse_associations_test.rb
+++ b/activerecord/test/cases/associations/inverse_associations_test.rb
@@ -114,7 +114,7 @@ class InverseHasOneTests < ActiveRecord::TestCase
   end
 
   def test_parent_instance_should_be_shared_with_newly_built_child
-    m = men(:gordon)
+    m = Man.find(:first)
     f = m.build_face(:description => 'haunted')
     assert_not_nil f.man
     assert_equal m.name, f.man.name, "Name of man should be the same before changes to parent instance"
@@ -125,7 +125,7 @@ class InverseHasOneTests < ActiveRecord::TestCase
   end
 
   def test_parent_instance_should_be_shared_with_newly_created_child
-    m = men(:gordon)
+    m = Man.find(:first)
     f = m.create_face(:description => 'haunted')
     assert_not_nil f.man
     assert_equal m.name, f.man.name, "Name of man should be the same before changes to parent instance"
@@ -146,39 +146,6 @@ class InverseHasOneTests < ActiveRecord::TestCase
     assert_equal m.name, f.man.name, "Name of man should be the same after changes to newly-created-child-owned instance"
   end
 
-  def test_parent_instance_should_be_shared_with_newly_built_child_when_we_dont_replace_existing
-    m = Man.find(:first)
-    f = m.build_face({:description => 'haunted'}, false)
-    assert_not_nil f.man
-    assert_equal m.name, f.man.name, "Name of man should be the same before changes to parent instance"
-    m.name = 'Bongo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to parent instance"
-    f.man.name = 'Mungo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to just-built-child-owned instance"
-  end
-
-  def test_parent_instance_should_be_shared_with_newly_created_child_when_we_dont_replace_existing
-    m = Man.find(:first)
-    f = m.create_face({:description => 'haunted'}, false)
-    assert_not_nil f.man
-    assert_equal m.name, f.man.name, "Name of man should be the same before changes to parent instance"
-    m.name = 'Bongo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to parent instance"
-    f.man.name = 'Mungo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to newly-created-child-owned instance"
-  end
-
-  def test_parent_instance_should_be_shared_with_newly_created_child_via_bang_method_when_we_dont_replace_existing
-    m = Man.find(:first)
-    f = m.face.create!({:description => 'haunted'}, false)
-    assert_not_nil f.man
-    assert_equal m.name, f.man.name, "Name of man should be the same before changes to parent instance"
-    m.name = 'Bongo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to parent instance"
-    f.man.name = 'Mungo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to newly-created-child-owned instance"
-  end
-
   def test_parent_instance_should_be_shared_with_replaced_via_accessor_child
     m = Man.find(:first)
     f = Face.new(:description => 'haunted')
@@ -203,18 +170,6 @@ class InverseHasOneTests < ActiveRecord::TestCase
     assert_equal m.name, f.man.name, "Name of man should be the same after changes to replaced-child-owned instance"
   end
 
-  def test_parent_instance_should_be_shared_with_replaced_via_method_child_when_we_dont_replace_existing
-    m = Man.find(:first)
-    f = Face.new(:description => 'haunted')
-    m.face.replace(f, false)
-    assert_not_nil f.man
-    assert_equal m.name, f.man.name, "Name of man should be the same before changes to parent instance"
-    m.name = 'Bongo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to parent instance"
-    f.man.name = 'Mungo'
-    assert_equal m.name, f.man.name, "Name of man should be the same after changes to replaced-child-owned instance"
-  end
-
   def test_trying_to_use_inverses_that_dont_exist_should_raise_an_error
     assert_raise(ActiveRecord::InverseOfAssociationNotFoundError) { Man.find(:first).dirty_face }
   end
@@ -257,17 +212,6 @@ class InverseHasManyTests < ActiveRecord::TestCase
     end
   end
 
-  def test_parent_instance_should_be_shared_with_newly_built_child
-    m = men(:gordon)
-    i = m.interests.build(:topic => 'Industrial Revolution Re-enactment')
-    assert_not_nil i.man
-    assert_equal m.name, i.man.name, "Name of man should be the same before changes to parent instance"
-    m.name = 'Bongo'
-    assert_equal m.name, i.man.name, "Name of man should be the same after changes to parent instance"
-    i.man.name = 'Mungo'
-    assert_equal m.name, i.man.name, "Name of man should be the same after changes to just-built-child-owned instance"
-  end
-
   def test_parent_instance_should_be_shared_with_newly_block_style_built_child
     m = Man.find(:first)
     i = m.interests.build {|ii| ii.topic = 'Industrial Revolution Re-enactment'}
@@ -280,17 +224,6 @@ class InverseHasManyTests < ActiveRecord::TestCase
     assert_equal m.name, i.man.name, "Name of man should be the same after changes to just-built-child-owned instance"
   end
 
-  def test_parent_instance_should_be_shared_with_newly_created_child
-    m = men(:gordon)
-    i = m.interests.create(:topic => 'Industrial Revolution Re-enactment')
-    assert_not_nil i.man
-    assert_equal m.name, i.man.name, "Name of man should be the same before changes to parent instance"
-    m.name = 'Bongo'
-    assert_equal m.name, i.man.name, "Name of man should be the same after changes to parent instance"
-    i.man.name = 'Mungo'
-    assert_equal m.name, i.man.name, "Name of man should be the same after changes to newly-created-child-owned instance"
-  end
-
   def test_parent_instance_should_be_shared_with_newly_created_via_bang_method_child
     m = Man.find(:first)
     i = m.interests.create!(:topic => 'Industrial Revolution Re-enactment')
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index d6e772e989..34f57d3155 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -13,7 +13,8 @@ require 'models/book'
 require 'models/citation'
 
 class AssociationsJoinModelTest < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
+
   fixtures :posts, :authors, :categories, :categorizations, :comments, :tags, :taggings, :author_favorites, :vertices, :items, :books,
     # Reload edges table from fixtures as otherwise repeated test was failing
     :edges
@@ -85,13 +86,6 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
     end
   end
 
-  def test_polymorphic_has_many_going_through_join_model_with_disabled_include
-    assert_equal tags(:general), tag = posts(:welcome).tags.add_joins_and_select.first
-    assert_queries 1 do
-      tag.tagging
-    end
-  end
-
   def test_polymorphic_has_many_going_through_join_model_with_custom_select_and_joins
     assert_equal tags(:general), tag = posts(:welcome).tags.add_joins_and_select.first
     assert_nothing_raised(NoMethodError) { tag.author_id }
@@ -340,11 +334,16 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
   end
 
   def test_has_many_polymorphic
-    assert_raise ActiveRecord::HasManyThroughAssociationPolymorphicError do
-      assert_equal posts(:welcome, :thinking), tags(:general).taggables
+    assert_raise ActiveRecord::HasManyThroughAssociationPolymorphicSourceError do
+      tags(:general).taggables
     end
+
+    assert_raise ActiveRecord::HasManyThroughAssociationPolymorphicThroughError do
+      taggings(:welcome_general).things
+    end
+
     assert_raise ActiveRecord::EagerLoadPolymorphicError do
-      assert_equal posts(:welcome, :thinking), tags(:general).taggings.find(:all, :include => :taggable, :conditions => 'bogus_table.column = 1')
+      tags(:general).taggings.find(:all, :include => :taggable, :conditions => 'bogus_table.column = 1')
     end
   end
 
@@ -512,6 +511,10 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
     assert_nothing_raised { vertices(:vertex_1).sinks << vertices(:vertex_5) }
   end
 
+  def test_add_to_join_table_with_no_id
+    assert_nothing_raised { vertices(:vertex_1).sinks << vertices(:vertex_5) }
+  end
+
   def test_has_many_through_collection_size_doesnt_load_target_if_not_loaded
     author = authors(:david)
     assert_equal 10, author.comments.size
@@ -520,7 +523,7 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
 
   def test_has_many_through_collection_size_uses_counter_cache_if_it_exists
     author = authors(:david)
-    author.stubs(:read_attribute).with('comments_count').returns(100)
+    author.stubs(:_read_attribute).with('comments_count').returns(100)
     assert_equal 100, author.comments.size
     assert !author.comments.loaded?
   end
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index 8214815bde..dfacf58da8 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -8,6 +8,7 @@ require 'models/topic'
 require 'models/company'
 require 'models/category'
 require 'models/reply'
+require 'models/contact'
 
 class AttributeMethodsTest < ActiveRecord::TestCase
   fixtures :topics, :developers, :companies, :computers
@@ -105,7 +106,7 @@ class AttributeMethodsTest < ActiveRecord::TestCase
 
   def test_read_attributes_before_type_cast
     category = Category.new({:name=>"Test categoty", :type => nil})
-    category_attrs = {"name"=>"Test categoty", "type" => nil, "categorizations_count" => nil}
+    category_attrs = {"name"=>"Test categoty", "id" => nil, "type" => nil, "categorizations_count" => nil}
     assert_equal category_attrs , category.attributes_before_type_cast
   end
 
@@ -116,24 +117,23 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     end
   end
 
-  unless current_adapter?(:Mysql2Adapter)
-    def test_read_attributes_before_type_cast_on_datetime
-      developer = Developer.find(:first)
-      # Oracle adapter returns Time before type cast
-      unless current_adapter?(:OracleAdapter)
-        assert_equal developer.created_at.to_s(:db) , developer.attributes_before_type_cast["created_at"].to_s
-      else
-        assert_equal developer.created_at.to_s(:db) , developer.attributes_before_type_cast["created_at"].to_s(:db)
+  def test_read_attributes_before_type_cast_on_datetime
+    developer = Developer.find(:first)
+    if current_adapter?(:Mysql2Adapter, :OracleAdapter)
+      # Mysql2 and Oracle adapters keep the value in Time instance
+      assert_equal developer.created_at.to_s(:db), developer.attributes_before_type_cast["created_at"].to_s(:db)
+    else
+      assert_equal developer.created_at.to_s(:db), developer.attributes_before_type_cast["created_at"].to_s
+    end
 
-        developer.created_at = "345643456"
-        assert_equal developer.created_at_before_type_cast, "345643456"
-        assert_equal developer.created_at, nil
+    developer.created_at = "345643456"
 
-        developer.created_at = "2010-03-21 21:23:32"
-        assert_equal developer.created_at_before_type_cast.to_s, "2010-03-21 21:23:32"
-        assert_equal developer.created_at, Time.parse("2010-03-21 21:23:32")
-      end
-    end
+    assert_equal developer.created_at_before_type_cast, "345643456"
+    assert_equal developer.created_at, nil
+
+    developer.created_at = "2010-03-21 21:23:32"
+    assert_equal developer.created_at_before_type_cast, "2010-03-21 21:23:32"
+    assert_equal developer.created_at, Time.parse("2010-03-21 21:23:32")
   end
 
   def test_hash_content
@@ -247,6 +247,12 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     # puts ""
   end
 
+  def test_read_overridden_attribute
+    topic = Topic.new(:title => 'a')
+    def topic.title() 'b' end
+    assert_equal 'a', topic[:title]
+  end
+
   def test_query_attribute_string
     [nil, "", " "].each do |value|
       assert_equal false, Topic.new(:author_name => value).author_name?
@@ -455,6 +461,14 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_write_nil_to_time_attributes
+    in_time_zone "Pacific Time (US & Canada)" do
+      record = @target.new
+      record.written_on = nil
+      assert_nil record.written_on
+    end
+  end
+
   def test_time_attributes_are_retrieved_in_current_time_zone
     in_time_zone "Pacific Time (US & Canada)" do
       utc_time = Time.utc(2008, 1, 1)
@@ -596,6 +610,10 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     Object.send(:undef_method, :title) # remove test method from object
   end
 
+  def test_list_of_serialized_attributes
+    assert_equal %w(content), Topic.serialized_attributes.keys
+    assert_equal %w(preferences), Contact.serialized_attributes.keys
+  end
 
   private
   def cached_columns
diff --git a/activerecord/test/cases/autosave_association_test.rb b/activerecord/test/cases/autosave_association_test.rb
index 0fd1e62134..8035cd2c6f 100644
--- a/activerecord/test/cases/autosave_association_test.rb
+++ b/activerecord/test/cases/autosave_association_test.rb
@@ -90,7 +90,7 @@ class TestDefaultAutosaveAssociationOnAHasOneAssociation < ActiveRecord::TestCas
     firm = Firm.find(:first)
     assert firm.valid?
 
-    firm.account = Account.new
+    firm.build_account
 
     assert !firm.account.valid?
     assert !firm.valid?
@@ -102,7 +102,7 @@ class TestDefaultAutosaveAssociationOnAHasOneAssociation < ActiveRecord::TestCas
     firm = Firm.find(:first)
     assert firm.valid?
 
-    firm.unvalidated_account = Account.new
+    firm.build_unvalidated_account
 
     assert !firm.unvalidated_account.valid?
     assert firm.valid?
@@ -340,6 +340,13 @@ class TestDefaultAutosaveAssociationOnABelongsToAssociation < ActiveRecord::Test
     tags(:misc).create_tagging(:taggable => posts(:thinking))
     assert_equal num_tagging + 1, Tagging.count
   end
+
+  def test_build_and_then_save_parent_should_not_reload_target
+    client = Client.find(:first)
+    apple = client.build_firm(:name => "Apple")
+    client.save!
+    assert_no_queries { assert_equal apple, client.firm }
+  end
 end
 
 class TestDefaultAutosaveAssociationOnAHasManyAssociation < ActiveRecord::TestCase
@@ -565,7 +572,7 @@ class TestDefaultAutosaveAssociationOnNewRecord < ActiveRecord::TestCase
 end
 
 class TestDestroyAsPartOfAutosaveAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.create(:catchphrase => "Don' botharrr talkin' like one, savvy?")
@@ -578,7 +585,7 @@ class TestDestroyAsPartOfAutosaveAssociation < ActiveRecord::TestCase
     @pirate.ship.mark_for_destruction
 
     assert !@pirate.reload.marked_for_destruction?
-    assert !@pirate.ship.marked_for_destruction?
+    assert !@pirate.ship.reload.marked_for_destruction?
   end
 
   # has_one
@@ -682,115 +689,212 @@ class TestDestroyAsPartOfAutosaveAssociation < ActiveRecord::TestCase
     assert_equal 'NewName', @parrot.reload.name
   end
 
-  # has_many & has_and_belongs_to
-  %w{ parrots birds }.each do |association_name|
-    define_method("test_should_destroy_#{association_name}_as_part_of_the_save_transaction_if_they_were_marked_for_destroyal") do
-      2.times { |i| @pirate.send(association_name).create!(:name => "#{association_name}_#{i}") }
+  def test_should_destroy_has_many_as_part_of_the_save_transaction_if_they_were_marked_for_destruction
+    2.times { |i| @pirate.birds.create!(:name => "birds_#{i}") }
 
-      assert !@pirate.send(association_name).any? { |child| child.marked_for_destruction? }
+    assert !@pirate.birds.any? { |child| child.marked_for_destruction? }
 
-      @pirate.send(association_name).each { |child| child.mark_for_destruction }
-      klass = @pirate.send(association_name).first.class
-      ids = @pirate.send(association_name).map(&:id)
+    @pirate.birds.each { |child| child.mark_for_destruction }
+    klass = @pirate.birds.first.class
+    ids = @pirate.birds.map(&:id)
 
-      assert @pirate.send(association_name).all? { |child| child.marked_for_destruction? }
-      ids.each { |id| assert klass.find_by_id(id) }
+    assert @pirate.birds.all? { |child| child.marked_for_destruction? }
+    ids.each { |id| assert klass.find_by_id(id) }
 
-      @pirate.save
-      assert @pirate.reload.send(association_name).empty?
-      ids.each { |id| assert_nil klass.find_by_id(id) }
+    @pirate.save
+    assert @pirate.reload.birds.empty?
+    ids.each { |id| assert_nil klass.find_by_id(id) }
+  end
+
+  def test_should_skip_validation_on_has_many_if_marked_for_destruction
+    2.times { |i| @pirate.birds.create!(:name => "birds_#{i}") }
+
+    @pirate.birds.each { |bird| bird.name = '' }
+    assert !@pirate.valid?
+
+    @pirate.birds.each do |bird|
+      bird.mark_for_destruction
+      bird.expects(:valid?).never
     end
+    assert_difference("Bird.count", -2) { @pirate.save! }
+  end
+
+  def test_should_skip_validation_on_has_many_if_destroyed
+    @pirate.birds.create!(:name => "birds_1")
+
+    @pirate.birds.each { |bird| bird.name = '' }
+    assert !@pirate.valid?
 
-    define_method("test_should_skip_validation_on_the_#{association_name}_association_if_marked_for_destruction") do
-      2.times { |i| @pirate.send(association_name).create!(:name => "#{association_name}_#{i}") }
-      children = @pirate.send(association_name)
+    @pirate.birds.each { |bird| bird.destroy }
+    assert @pirate.valid?
+  end
 
-      children.each { |child| child.name = '' }
-      assert !@pirate.valid?
+  def test_a_child_marked_for_destruction_should_not_be_destroyed_twice_while_saving_has_many
+    @pirate.birds.create!(:name => "birds_1")
+
+    @pirate.birds.each { |bird| bird.mark_for_destruction }
+    assert @pirate.save
 
-      children.each do |child|
-        child.mark_for_destruction
-        child.expects(:valid?).never
+    @pirate.birds.each { |bird| bird.expects(:destroy).never }
+    assert @pirate.save
+  end
+
+  def test_should_rollback_destructions_if_an_exception_occurred_while_saving_has_many
+    2.times { |i| @pirate.birds.create!(:name => "birds_#{i}") }
+    before = @pirate.birds.map { |c| c.mark_for_destruction ; c }
+
+    # Stub the destroy method of the the second child to raise an exception
+    class << before.last
+      def destroy(*args)
+        super
+        raise 'Oh noes!'
       end
-      assert_difference("#{association_name.classify}.count", -2) { @pirate.save! }
     end
 
-    define_method("test_should_skip_validation_on_the_#{association_name}_association_if_destroyed") do
-      @pirate.send(association_name).create!(:name => "#{association_name}_1")
-      children = @pirate.send(association_name)
+    assert_raise(RuntimeError) { assert !@pirate.save }
+    assert_equal before, @pirate.reload.birds
+  end
+
+  # Add and remove callbacks tests for association collections.
+  %w{ method proc }.each do |callback_type|
+    define_method("test_should_run_add_callback_#{callback_type}s_for_has_many") do
+      association_name_with_callbacks = "birds_with_#{callback_type}_callbacks"
+
+      pirate = Pirate.new(:catchphrase => "Arr")
+      pirate.send(association_name_with_callbacks).build(:name => "Crowe the One-Eyed")
 
-      children.each { |child| child.name = '' }
-      assert !@pirate.valid?
+      expected = [
+        "before_adding_#{callback_type}_bird_<new>",
+        "after_adding_#{callback_type}_bird_<new>"
+      ]
 
-      children.each { |child| child.destroy }
-      assert @pirate.valid?
+      assert_equal expected, pirate.ship_log
     end
 
-    define_method("test_a_child_marked_for_destruction_should_not_be_destroyed_twice_while_saving_#{association_name}") do
-      @pirate.send(association_name).create!(:name => "#{association_name}_1")
-      children = @pirate.send(association_name)
+    define_method("test_should_run_remove_callback_#{callback_type}s_for_has_many") do
+      association_name_with_callbacks = "birds_with_#{callback_type}_callbacks"
 
-      children.each { |child| child.mark_for_destruction }
-      assert @pirate.save
-      children.each { |child| child.expects(:destroy).never }
-      assert @pirate.save
+      @pirate.send(association_name_with_callbacks).create!(:name => "Crowe the One-Eyed")
+      @pirate.send(association_name_with_callbacks).each { |c| c.mark_for_destruction }
+      child_id = @pirate.send(association_name_with_callbacks).first.id
+
+      @pirate.ship_log.clear
+      @pirate.save
+
+      expected = [
+        "before_removing_#{callback_type}_bird_#{child_id}",
+        "after_removing_#{callback_type}_bird_#{child_id}"
+      ]
+
+      assert_equal expected, @pirate.ship_log
     end
+  end
 
-    define_method("test_should_rollback_destructions_if_an_exception_occurred_while_saving_#{association_name}") do
-      2.times { |i| @pirate.send(association_name).create!(:name => "#{association_name}_#{i}") }
-      before = @pirate.send(association_name).map { |c| c.mark_for_destruction ; c }
+  def test_should_destroy_habtm_as_part_of_the_save_transaction_if_they_were_marked_for_destruction
+    2.times { |i| @pirate.parrots.create!(:name => "parrots_#{i}") }
 
-      # Stub the destroy method of the the second child to raise an exception
-      class << before.last
-        def destroy(*args)
-          super
-          raise 'Oh noes!'
-        end
-      end
+    assert !@pirate.parrots.any? { |parrot| parrot.marked_for_destruction? }
+    @pirate.parrots.each { |parrot| parrot.mark_for_destruction }
 
-      assert_raise(RuntimeError) { assert !@pirate.save }
-      assert_equal before, @pirate.reload.send(association_name)
+    assert_no_difference "Parrot.count" do
+      @pirate.save
     end
 
-    # Add and remove callbacks tests for association collections.
-    %w{ method proc }.each do |callback_type|
-      define_method("test_should_run_add_callback_#{callback_type}s_for_#{association_name}") do
-        association_name_with_callbacks = "#{association_name}_with_#{callback_type}_callbacks"
+    assert @pirate.reload.parrots.empty?
 
-        pirate = Pirate.new(:catchphrase => "Arr")
-        pirate.send(association_name_with_callbacks).build(:name => "Crowe the One-Eyed")
+    join_records = Pirate.connection.select_all("SELECT * FROM parrots_pirates WHERE pirate_id = #{@pirate.id}")
+    assert join_records.empty?
+  end
 
-        expected = [
-          "before_adding_#{callback_type}_#{association_name.singularize}_<new>",
-          "after_adding_#{callback_type}_#{association_name.singularize}_<new>"
-        ]
+  def test_should_skip_validation_on_habtm_if_marked_for_destruction
+    2.times { |i| @pirate.parrots.create!(:name => "parrots_#{i}") }
 
-        assert_equal expected, pirate.ship_log
-      end
+    @pirate.parrots.each { |parrot| parrot.name = '' }
+    assert !@pirate.valid?
 
-      define_method("test_should_run_remove_callback_#{callback_type}s_for_#{association_name}") do
-        association_name_with_callbacks = "#{association_name}_with_#{callback_type}_callbacks"
+    @pirate.parrots.each do |parrot|
+      parrot.mark_for_destruction
+      parrot.expects(:valid?).never
+    end
 
-        @pirate.send(association_name_with_callbacks).create!(:name => "Crowe the One-Eyed")
-        @pirate.send(association_name_with_callbacks).each { |c| c.mark_for_destruction }
-        child_id = @pirate.send(association_name_with_callbacks).first.id
+    @pirate.save!
+    assert @pirate.reload.parrots.empty?
+  end
+
+  def test_should_skip_validation_on_habtm_if_destroyed
+    @pirate.parrots.create!(:name => "parrots_1")
 
-        @pirate.ship_log.clear
-        @pirate.save
+    @pirate.parrots.each { |parrot| parrot.name = '' }
+    assert !@pirate.valid?
 
-        expected = [
-          "before_removing_#{callback_type}_#{association_name.singularize}_#{child_id}",
-          "after_removing_#{callback_type}_#{association_name.singularize}_#{child_id}"
-        ]
+    @pirate.parrots.each { |parrot| parrot.destroy }
+    assert @pirate.valid?
+  end
+
+  def test_a_child_marked_for_destruction_should_not_be_destroyed_twice_while_saving_habtm
+    @pirate.parrots.create!(:name => "parrots_1")
+
+    @pirate.parrots.each { |parrot| parrot.mark_for_destruction }
+    assert @pirate.save
+
+    assert_no_queries do
+      assert @pirate.save
+    end
+  end
 
-        assert_equal expected, @pirate.ship_log
+  def test_should_rollback_destructions_if_an_exception_occurred_while_saving_habtm
+    2.times { |i| @pirate.parrots.create!(:name => "parrots_#{i}") }
+    before = @pirate.parrots.map { |c| c.mark_for_destruction ; c }
+
+    class << @pirate.parrots
+      def destroy(*args)
+        super
+        raise 'Oh noes!'
       end
     end
+
+    assert_raise(RuntimeError) { assert !@pirate.save }
+    assert_equal before, @pirate.reload.parrots
+  end
+
+  # Add and remove callbacks tests for association collections.
+  %w{ method proc }.each do |callback_type|
+    define_method("test_should_run_add_callback_#{callback_type}s_for_habtm") do
+      association_name_with_callbacks = "parrots_with_#{callback_type}_callbacks"
+
+      pirate = Pirate.new(:catchphrase => "Arr")
+      pirate.send(association_name_with_callbacks).build(:name => "Crowe the One-Eyed")
+
+      expected = [
+        "before_adding_#{callback_type}_parrot_<new>",
+        "after_adding_#{callback_type}_parrot_<new>"
+      ]
+
+      assert_equal expected, pirate.ship_log
+    end
+
+    define_method("test_should_run_remove_callback_#{callback_type}s_for_habtm") do
+      association_name_with_callbacks = "parrots_with_#{callback_type}_callbacks"
+
+      @pirate.send(association_name_with_callbacks).create!(:name => "Crowe the One-Eyed")
+      @pirate.send(association_name_with_callbacks).each { |c| c.mark_for_destruction }
+      child_id = @pirate.send(association_name_with_callbacks).first.id
+
+      @pirate.ship_log.clear
+      @pirate.save
+
+      expected = [
+        "before_removing_#{callback_type}_parrot_#{child_id}",
+        "after_removing_#{callback_type}_parrot_#{child_id}"
+      ]
+
+      assert_equal expected, @pirate.ship_log
+    end
   end
 end
 
 class TestAutosaveAssociationOnAHasOneAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.create(:catchphrase => "Don' botharrr talkin' like one, savvy?")
@@ -910,7 +1014,7 @@ class TestAutosaveAssociationOnAHasOneAssociation < ActiveRecord::TestCase
 end
 
 class TestAutosaveAssociationOnABelongsToAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @ship = Ship.create(:name => 'Nights Dirty Lightning')
@@ -1157,7 +1261,7 @@ module AutosaveAssociationOnACollectionAssociationTests
 end
 
 class TestAutosaveAssociationOnAHasManyAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @association_name = :birds
@@ -1171,7 +1275,7 @@ class TestAutosaveAssociationOnAHasManyAssociation < ActiveRecord::TestCase
 end
 
 class TestAutosaveAssociationOnAHasAndBelongsToManyAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @association_name = :parrots
@@ -1186,7 +1290,7 @@ class TestAutosaveAssociationOnAHasAndBelongsToManyAssociation < ActiveRecord::T
 end
 
 class TestAutosaveAssociationValidationsOnAHasManyAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.create(:catchphrase => "Don' botharrr talkin' like one, savvy?")
@@ -1202,7 +1306,7 @@ class TestAutosaveAssociationValidationsOnAHasManyAssociation < ActiveRecord::Te
 end
 
 class TestAutosaveAssociationValidationsOnAHasOneAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.create(:catchphrase => "Don' botharrr talkin' like one, savvy?")
@@ -1224,7 +1328,7 @@ class TestAutosaveAssociationValidationsOnAHasOneAssociation < ActiveRecord::Tes
 end
 
 class TestAutosaveAssociationValidationsOnABelongsToAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.create(:catchphrase => "Don' botharrr talkin' like one, savvy?")
@@ -1244,7 +1348,7 @@ class TestAutosaveAssociationValidationsOnABelongsToAssociation < ActiveRecord::
 end
 
 class TestAutosaveAssociationValidationsOnAHABTMAssociation < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.create(:catchphrase => "Don' botharrr talkin' like one, savvy?")
@@ -1266,7 +1370,7 @@ class TestAutosaveAssociationValidationsOnAHABTMAssociation < ActiveRecord::Test
 end
 
 class TestAutosaveAssociationValidationMethodsGeneration < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.new
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index 86d4a90fc4..0ad20bb9bc 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -19,6 +19,8 @@ require 'models/minimalistic'
 require 'models/warehouse_thing'
 require 'models/parrot'
 require 'models/loose_person'
+require 'models/edge'
+require 'models/joke'
 require 'rexml/document'
 require 'active_support/core_ext/exception'
 
@@ -48,6 +50,57 @@ class Boolean < ActiveRecord::Base; end
 class BasicsTest < ActiveRecord::TestCase
   fixtures :topics, :companies, :developers, :projects, :computers, :accounts, :minimalistics, 'warehouse-things', :authors, :categorizations, :categories, :posts
 
+  def test_columns_should_obey_set_primary_key
+    pk = Subscriber.columns.find { |x| x.name == 'nick' }
+    assert pk.primary, 'nick should be primary key'
+  end
+
+  def test_primary_key_with_no_id
+    assert_nil Edge.primary_key
+  end
+
+  unless current_adapter?(:PostgreSQLAdapter,:OracleAdapter,:SQLServerAdapter)
+    def test_limit_with_comma
+      assert_nothing_raised do
+        Topic.limit("1,2").all
+      end
+    end
+  end
+
+  def test_limit_without_comma
+    assert_nothing_raised do
+      assert_equal 1, Topic.limit("1").all.length
+    end
+
+    assert_nothing_raised do
+      assert_equal 1, Topic.limit(1).all.length
+    end
+  end
+
+  def test_invalid_limit
+    assert_raises(ArgumentError) do
+      Topic.limit("asdfadf").all
+    end
+  end
+
+  def test_limit_should_sanitize_sql_injection_for_limit_without_comas
+    assert_raises(ArgumentError) do
+      Topic.limit("1 select * from schema").all
+    end
+  end
+
+  def test_limit_should_sanitize_sql_injection_for_limit_with_comas
+    assert_raises(ArgumentError) do
+      Topic.limit("1, 7 procedure help()").all
+    end
+  end
+
+  unless current_adapter?(:MysqlAdapter) || current_adapter?(:Mysql2Adapter)
+    def test_limit_should_allow_sql_literal
+      assert_equal 1, Topic.limit(Arel.sql('2-1')).all.length
+    end
+  end
+
   def test_select_symbol
     topic_ids = Topic.select(:id).map(&:id).sort
     assert_equal Topic.find(:all).map(&:id).sort, topic_ids
@@ -698,7 +751,7 @@ class BasicsTest < ActiveRecord::TestCase
 
     duped_topic.reload
     # FIXME: I think this is poor behavior, and will fix it with #5686
-    assert_equal({'a' => 'c'}.to_s, duped_topic.title)
+    assert_equal({'a' => 'c'}.to_yaml, duped_topic.title)
   end
 
   def test_dup_with_aggregate_of_same_name_as_attribute
@@ -997,6 +1050,25 @@ class BasicsTest < ActiveRecord::TestCase
     Topic.serialize(:content)
   end
 
+  def test_serialized_default_class
+    Topic.serialize(:content, Hash)
+    topic = Topic.new
+    assert_equal Hash, topic.content.class
+    assert_equal Hash, topic.read_attribute(:content).class
+    topic.content["beer"] = "MadridRb"
+    assert topic.save
+    topic.reload
+    assert_equal Hash, topic.content.class
+    assert_equal "MadridRb", topic.content["beer"]
+  ensure
+    Topic.serialize(:content)
+  end
+
+  def test_serialized_no_default_class_for_object
+    topic = Topic.new
+    assert_nil topic.content
+  end
+
   def test_serialized_boolean_value_true
     Topic.serialize(:content)
     topic = Topic.new(:content => true)
@@ -1013,6 +1085,52 @@ class BasicsTest < ActiveRecord::TestCase
     assert_equal topic.content, false
   end
 
+  def test_serialize_with_coder
+    coder = Class.new {
+      # Identity
+      def load(thing)
+        thing
+      end
+
+      # base 64
+      def dump(thing)
+        [thing].pack('m')
+      end
+    }.new
+
+    Topic.serialize(:content, coder)
+    s = 'hello world'
+    topic = Topic.new(:content => s)
+    assert topic.save
+    topic = topic.reload
+    assert_equal [s].pack('m'), topic.content
+  ensure
+    Topic.serialize(:content)
+  end
+
+  def test_serialize_with_bcrypt_coder
+    crypt_coder = Class.new {
+      def load(thing)
+        return unless thing
+        BCrypt::Password.new thing
+      end
+
+      def dump(thing)
+        BCrypt::Password.create(thing).to_s
+      end
+    }.new
+
+    Topic.serialize(:content, crypt_coder)
+    password = 'password'
+    topic = Topic.new(:content => password)
+    assert topic.save
+    topic = topic.reload
+    assert_kind_of BCrypt::Password, topic.content
+    assert_equal(true, topic.content == password, 'password should equal')
+  ensure
+    Topic.serialize(:content)
+  end
+
   def test_quote
     author_name = "\\ \001 ' \n \\n \""
     topic = Topic.create('author_name' => author_name)
@@ -1068,9 +1186,14 @@ class BasicsTest < ActiveRecord::TestCase
   end
 
   def test_define_attr_method_with_block
-    k = Class.new( ActiveRecord::Base )
-    k.send(:define_attr_method, :primary_key) { "sys_" + original_primary_key }
-    assert_equal "sys_id", k.primary_key
+    k = Class.new( ActiveRecord::Base ) do
+      class << self
+        attr_accessor :foo_key
+      end
+    end
+    k.foo_key = "id"
+    k.send(:define_attr_method, :foo_key) { "sys_" + original_foo_key }
+    assert_equal "sys_id", k.foo_key
   end
 
   def test_set_table_name_with_value
@@ -1081,6 +1204,16 @@ class BasicsTest < ActiveRecord::TestCase
     assert_equal "bar", k.table_name
   end
 
+  def test_switching_between_table_name
+    assert_difference("GoodJoke.count") do
+      Joke.set_table_name "cold_jokes"
+      Joke.create
+
+      Joke.set_table_name "funny_jokes"
+      Joke.create
+    end
+  end
+
   def test_quoted_table_name_after_set_table_name
     klass = Class.new(ActiveRecord::Base)
 
@@ -1109,6 +1242,7 @@ class BasicsTest < ActiveRecord::TestCase
 
   def test_set_primary_key_with_block
     k = Class.new( ActiveRecord::Base )
+    k.primary_key = 'id'
     k.set_primary_key { "sys_" + original_primary_key }
     assert_equal "sys_id", k.primary_key
   end
@@ -1161,12 +1295,6 @@ class BasicsTest < ActiveRecord::TestCase
     assert_equal res6, res7
   end
 
-  def test_interpolate_sql
-    assert_nothing_raised { Category.new.send(:interpolate_sql, 'foo@bar') }
-    assert_nothing_raised { Category.new.send(:interpolate_sql, 'foo bar) baz') }
-    assert_nothing_raised { Category.new.send(:interpolate_sql, 'foo bar} baz') }
-  end
-
   def test_scoped_find_conditions
     scoped_developers = Developer.send(:with_scope, :find => { :conditions => 'salary > 90000' }) do
       Developer.find(:all, :conditions => 'id < 5')
@@ -1477,6 +1605,14 @@ class BasicsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_clear_cache!
+    # preheat cache
+    c1 = Post.columns
+    ActiveRecord::Base.clear_cache!
+    c2 = Post.columns
+    assert_not_equal c1, c2
+  end
+
   def test_default_scope_is_reset
     Object.const_set :UnloadablePost, Class.new(ActiveRecord::Base)
     UnloadablePost.table_name = 'posts'
@@ -1492,4 +1628,11 @@ class BasicsTest < ActiveRecord::TestCase
   ensure
     Object.class_eval{ remove_const :UnloadablePost } if defined?(UnloadablePost)
   end
+
+  def test_marshal_round_trip
+    expected = posts(:welcome)
+    actual   = Marshal.load(Marshal.dump(expected))
+
+    assert_equal expected.attributes, actual.attributes
+  end
 end
diff --git a/activerecord/test/cases/batches_test.rb b/activerecord/test/cases/batches_test.rb
index dcc49e12ca..6f65fb96d1 100644
--- a/activerecord/test/cases/batches_test.rb
+++ b/activerecord/test/cases/batches_test.rb
@@ -7,6 +7,7 @@ class EachTest < ActiveRecord::TestCase
   def setup
     @posts = Post.order("id asc")
     @total = Post.count
+    Post.count('id') # preheat arel's table cache
   end
 
   def test_each_should_excecute_one_query_per_batch
diff --git a/activerecord/test/cases/bind_parameter_test.rb b/activerecord/test/cases/bind_parameter_test.rb
new file mode 100644
index 0000000000..19383bb06b
--- /dev/null
+++ b/activerecord/test/cases/bind_parameter_test.rb
@@ -0,0 +1,90 @@
+require 'cases/helper'
+require 'models/topic'
+
+module ActiveRecord
+  class BindParameterTest < ActiveRecord::TestCase
+    fixtures :topics
+
+    class LogListener
+      attr_accessor :calls
+
+      def initialize
+        @calls = []
+      end
+
+      def call(*args)
+        calls << args
+      end
+    end
+
+    def setup
+      super
+      @connection = ActiveRecord::Base.connection
+      @listener   = LogListener.new
+      @pk         = Topic.columns.find { |c| c.primary }
+      ActiveSupport::Notifications.subscribe('sql.active_record', @listener)
+    end
+
+    def teardown
+      ActiveSupport::Notifications.unsubscribe(@listener)
+    end
+
+    def test_binds_are_logged
+      # FIXME: use skip with minitest
+      return unless @connection.supports_statement_cache?
+
+      sub   = @connection.substitute_for(@pk, [])
+      binds = [[@pk, 1]]
+      sql   = "select * from topics where id = #{sub}"
+
+      @connection.exec_query(sql, 'SQL', binds)
+
+      message = @listener.calls.find { |args| args[4][:sql] == sql }
+      assert_equal binds, message[4][:binds]
+    end
+
+    def test_find_one_uses_binds
+      # FIXME: use skip with minitest
+      return unless @connection.supports_statement_cache?
+
+      Topic.find(1)
+      binds = [[@pk, 1]]
+      message = @listener.calls.find { |args| args[4][:binds] == binds }
+      assert message, 'expected a message with binds'
+    end
+
+    def test_logs_bind_vars
+      # FIXME: use skip with minitest
+      return unless @connection.supports_statement_cache?
+
+      pk = Topic.columns.find { |x| x.primary }
+
+      payload = {
+        :name  => 'SQL',
+        :sql   => 'select * from topics where id = ?',
+        :binds => [[pk, 10]]
+      }
+      event  = ActiveSupport::Notifications::Event.new(
+        'foo',
+        Time.now,
+        Time.now,
+        123,
+        payload)
+
+        logger = Class.new(ActiveRecord::LogSubscriber) {
+          attr_reader :debugs
+          def initialize
+            super
+            @debugs = []
+          end
+
+          def debug str
+            @debugs << str
+          end
+        }.new
+
+        logger.sql event
+        assert_match([[pk.name, 10]].inspect, logger.debugs.first)
+    end
+  end
+end
diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index 5cb8485b4b..3121f1615d 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -23,6 +23,17 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal 53.0, value
   end
 
+  def test_should_return_decimal_average_of_integer_field
+    value = Account.average(:id)
+    assert_equal 3.5, value
+  end
+
+  def test_should_return_integer_average_if_db_returns_such
+    Account.connection.stubs :select_value => 3
+    value = Account.average(:id)
+    assert_equal 3, value
+  end
+
   def test_should_return_nil_as_average
     assert_nil NumericData.average(:bank_balance)
   end
diff --git a/activerecord/test/cases/coders/yaml_column_test.rb b/activerecord/test/cases/coders/yaml_column_test.rb
new file mode 100644
index 0000000000..c7dcc21809
--- /dev/null
+++ b/activerecord/test/cases/coders/yaml_column_test.rb
@@ -0,0 +1,46 @@
+
+require "cases/helper"
+
+module ActiveRecord
+  module Coders
+    class YAMLColumnTest < ActiveRecord::TestCase
+      def test_initialize_takes_class
+        coder = YAMLColumn.new(Object)
+        assert_equal Object, coder.object_class
+      end
+
+      def test_type_mismatch_on_different_classes
+        coder = YAMLColumn.new(Array)
+        assert_raises(SerializationTypeMismatch) do
+          coder.load "--- foo"
+        end
+      end
+
+      def test_nil_is_ok
+        coder = YAMLColumn.new
+        assert_nil coder.load "--- "
+      end
+
+      def test_returns_new_with_different_class
+        coder = YAMLColumn.new SerializationTypeMismatch
+        assert_equal SerializationTypeMismatch, coder.load("--- ").class
+      end
+
+      def test_returns_string_unless_starts_with_dash
+        coder = YAMLColumn.new
+        assert_equal 'foo', coder.load("foo")
+      end
+
+      def test_load_handles_other_classes
+        coder = YAMLColumn.new
+        assert_equal [], coder.load([])
+      end
+
+      def test_load_swallows_yaml_exceptions
+        coder = YAMLColumn.new
+        bad_yaml = '--- {'
+        assert_equal bad_yaml, coder.load(bad_yaml)
+      end
+    end
+  end
+end
diff --git a/activerecord/test/cases/column_definition_test.rb b/activerecord/test/cases/column_definition_test.rb
index cc6a6b44f2..d1dddd4c2c 100644
--- a/activerecord/test/cases/column_definition_test.rb
+++ b/activerecord/test/cases/column_definition_test.rb
@@ -1,121 +1,145 @@
 require "cases/helper"
 
-class ColumnDefinitionTest < ActiveRecord::TestCase
-  def setup
-    @adapter = ActiveRecord::ConnectionAdapters::AbstractAdapter.new(nil)
-    def @adapter.native_database_types
-      {:string => "varchar"}
-    end
-  end
+module ActiveRecord
+  module ConnectionAdapters
+    class ColumnDefinitionTest < ActiveRecord::TestCase
+      def setup
+        @adapter = AbstractAdapter.new(nil)
+        def @adapter.native_database_types
+          {:string => "varchar"}
+        end
+      end
 
-  # Avoid column definitions in create table statements like:
-  # `title` varchar(255) DEFAULT NULL
-  def test_should_not_include_default_clause_when_default_is_null
-    column = ActiveRecord::ConnectionAdapters::Column.new("title", nil, "varchar(20)")
-    column_def = ActiveRecord::ConnectionAdapters::ColumnDefinition.new(
-      @adapter, column.name, "string",
-      column.limit, column.precision, column.scale, column.default, column.null)
-    assert_equal "title varchar(20)", column_def.to_sql
-  end
+      def test_can_set_coder
+        column = Column.new("title", nil, "varchar(20)")
+        column.coder = YAML
+        assert_equal YAML, column.coder
+      end
 
-  def test_should_include_default_clause_when_default_is_present
-    column = ActiveRecord::ConnectionAdapters::Column.new("title", "Hello", "varchar(20)")
-    column_def = ActiveRecord::ConnectionAdapters::ColumnDefinition.new(
-      @adapter, column.name, "string",
-      column.limit, column.precision, column.scale, column.default, column.null)
-    assert_equal %Q{title varchar(20) DEFAULT 'Hello'}, column_def.to_sql
-  end
+      def test_encoded?
+        column = Column.new("title", nil, "varchar(20)")
+        assert !column.encoded?
 
-  def test_should_specify_not_null_if_null_option_is_false
-    column = ActiveRecord::ConnectionAdapters::Column.new("title", "Hello", "varchar(20)", false)
-    column_def = ActiveRecord::ConnectionAdapters::ColumnDefinition.new(
-      @adapter, column.name, "string",
-      column.limit, column.precision, column.scale, column.default, column.null)
-    assert_equal %Q{title varchar(20) DEFAULT 'Hello' NOT NULL}, column_def.to_sql
-  end
+        column.coder = YAML
+        assert column.encoded?
+      end
 
-  if current_adapter?(:MysqlAdapter)
-    def test_should_set_default_for_mysql_binary_data_types
-      binary_column = ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", "a", "binary(1)")
-      assert_equal "a", binary_column.default
+      def test_type_case_coded_column
+        column = Column.new("title", nil, "varchar(20)")
+        column.coder = YAML
+        assert_equal "hello", column.type_cast("--- hello")
+      end
 
-      varbinary_column = ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", "a", "varbinary(1)")
-      assert_equal "a", varbinary_column.default
-    end
+      # Avoid column definitions in create table statements like:
+      # `title` varchar(255) DEFAULT NULL
+      def test_should_not_include_default_clause_when_default_is_null
+        column = Column.new("title", nil, "varchar(20)")
+        column_def = ColumnDefinition.new(
+          @adapter, column.name, "string",
+          column.limit, column.precision, column.scale, column.default, column.null)
+          assert_equal "title varchar(20)", column_def.to_sql
+      end
 
-    def test_should_not_set_default_for_blob_and_text_data_types
-      assert_raise ArgumentError do
-        ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", "a", "blob")
+      def test_should_include_default_clause_when_default_is_present
+        column = Column.new("title", "Hello", "varchar(20)")
+        column_def = ColumnDefinition.new(
+          @adapter, column.name, "string",
+          column.limit, column.precision, column.scale, column.default, column.null)
+          assert_equal %Q{title varchar(20) DEFAULT 'Hello'}, column_def.to_sql
       end
 
-      assert_raise ArgumentError do
-        ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", "Hello", "text")
+      def test_should_specify_not_null_if_null_option_is_false
+        column = Column.new("title", "Hello", "varchar(20)", false)
+        column_def = ColumnDefinition.new(
+          @adapter, column.name, "string",
+          column.limit, column.precision, column.scale, column.default, column.null)
+          assert_equal %Q{title varchar(20) DEFAULT 'Hello' NOT NULL}, column_def.to_sql
       end
 
-      text_column = ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", nil, "text")
-      assert_equal nil, text_column.default
+      if current_adapter?(:MysqlAdapter)
+        def test_should_set_default_for_mysql_binary_data_types
+          binary_column = MysqlColumn.new("title", "a", "binary(1)")
+          assert_equal "a", binary_column.default
 
-      not_null_text_column = ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", nil, "text", false)
-      assert_equal "", not_null_text_column.default
-    end
+          varbinary_column = MysqlColumn.new("title", "a", "varbinary(1)")
+          assert_equal "a", varbinary_column.default
+        end
 
-    def test_has_default_should_return_false_for_blog_and_test_data_types
-      blob_column = ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", nil, "blob")
-      assert !blob_column.has_default?
+        def test_should_not_set_default_for_blob_and_text_data_types
+          assert_raise ArgumentError do
+            MysqlColumn.new("title", "a", "blob")
+          end
 
-      text_column = ActiveRecord::ConnectionAdapters::MysqlColumn.new("title", nil, "text")
-      assert !text_column.has_default?
-    end
-  end
+          assert_raise ArgumentError do
+            MysqlColumn.new("title", "Hello", "text")
+          end
 
-  if current_adapter?(:Mysql2Adapter)
-    def test_should_set_default_for_mysql_binary_data_types
-      binary_column = ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", "a", "binary(1)")
-      assert_equal "a", binary_column.default
+          text_column = MysqlColumn.new("title", nil, "text")
+          assert_equal nil, text_column.default
 
-      varbinary_column = ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", "a", "varbinary(1)")
-      assert_equal "a", varbinary_column.default
-    end
+          not_null_text_column = MysqlColumn.new("title", nil, "text", false)
+          assert_equal "", not_null_text_column.default
+        end
 
-    def test_should_not_set_default_for_blob_and_text_data_types
-      assert_raise ArgumentError do
-        ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", "a", "blob")
-      end
+        def test_has_default_should_return_false_for_blog_and_test_data_types
+          blob_column = MysqlColumn.new("title", nil, "blob")
+          assert !blob_column.has_default?
 
-      assert_raise ArgumentError do
-        ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", "Hello", "text")
+          text_column = MysqlColumn.new("title", nil, "text")
+          assert !text_column.has_default?
+        end
       end
 
-      text_column = ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", nil, "text")
-      assert_equal nil, text_column.default
+      if current_adapter?(:Mysql2Adapter)
+        def test_should_set_default_for_mysql_binary_data_types
+          binary_column = Mysql2Column.new("title", "a", "binary(1)")
+          assert_equal "a", binary_column.default
 
-      not_null_text_column = ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", nil, "text", false)
-      assert_equal "", not_null_text_column.default
-    end
+          varbinary_column = Mysql2Column.new("title", "a", "varbinary(1)")
+          assert_equal "a", varbinary_column.default
+        end
 
-    def test_has_default_should_return_false_for_blog_and_test_data_types
-      blob_column = ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", nil, "blob")
-      assert !blob_column.has_default?
+        def test_should_not_set_default_for_blob_and_text_data_types
+          assert_raise ArgumentError do
+            Mysql2Column.new("title", "a", "blob")
+          end
 
-      text_column = ActiveRecord::ConnectionAdapters::Mysql2Column.new("title", nil, "text")
-      assert !text_column.has_default?
-    end
-  end
+          assert_raise ArgumentError do
+            Mysql2Column.new("title", "Hello", "text")
+          end
 
-  if current_adapter?(:PostgreSQLAdapter)
-    def test_bigint_column_should_map_to_integer
-      bigint_column = ActiveRecord::ConnectionAdapters::PostgreSQLColumn.new('number', nil, "bigint")
-      assert_equal :integer, bigint_column.type
-    end
+          text_column = Mysql2Column.new("title", nil, "text")
+          assert_equal nil, text_column.default
 
-    def test_smallint_column_should_map_to_integer
-      smallint_column = ActiveRecord::ConnectionAdapters::PostgreSQLColumn.new('number', nil, "smallint")
-      assert_equal :integer, smallint_column.type
-    end
+          not_null_text_column = Mysql2Column.new("title", nil, "text", false)
+          assert_equal "", not_null_text_column.default
+        end
+
+        def test_has_default_should_return_false_for_blog_and_test_data_types
+          blob_column = Mysql2Column.new("title", nil, "blob")
+          assert !blob_column.has_default?
 
-    def test_uuid_column_should_map_to_string
-      uuid_column = ActiveRecord::ConnectionAdapters::PostgreSQLColumn.new('unique_id', nil, "uuid")
-      assert_equal :string, uuid_column.type
+          text_column = Mysql2Column.new("title", nil, "text")
+          assert !text_column.has_default?
+        end
+      end
+
+      if current_adapter?(:PostgreSQLAdapter)
+        def test_bigint_column_should_map_to_integer
+          bigint_column = PostgreSQLColumn.new('number', nil, "bigint")
+          assert_equal :integer, bigint_column.type
+        end
+
+        def test_smallint_column_should_map_to_integer
+          smallint_column = PostgreSQLColumn.new('number', nil, "smallint")
+          assert_equal :integer, smallint_column.type
+        end
+
+        def test_uuid_column_should_map_to_string
+          uuid_column = PostgreSQLColumn.new('unique_id', nil, "uuid")
+          assert_equal :string, uuid_column.type
+        end
+      end
     end
   end
 end
diff --git a/activerecord/test/cases/connection_pool_test.rb b/activerecord/test/cases/connection_pool_test.rb
index 2e18117895..7ac14fa8d6 100644
--- a/activerecord/test/cases/connection_pool_test.rb
+++ b/activerecord/test/cases/connection_pool_test.rb
@@ -3,6 +3,58 @@ require "cases/helper"
 module ActiveRecord
   module ConnectionAdapters
     class ConnectionPoolTest < ActiveRecord::TestCase
+      def setup
+        # Keep a duplicate pool so we do not bother others
+        @pool = ConnectionPool.new ActiveRecord::Base.connection_pool.spec
+
+        if in_memory_db?
+          # Separate connections to an in-memory database create an entirely new database,
+          # with an empty schema etc, so we just stub out this schema on the fly.
+          @pool.with_connection do |connection|
+            connection.create_table :posts do |t|
+              t.integer :cololumn
+            end
+          end
+        end
+      end
+
+      def test_pool_caches_columns
+        columns = @pool.columns['posts']
+        assert_equal columns, @pool.columns['posts']
+      end
+
+      def test_pool_caches_columns_hash
+        columns_hash = @pool.columns_hash['posts']
+        assert_equal columns_hash, @pool.columns_hash['posts']
+      end
+
+      def test_clearing_column_cache
+        @pool.columns['posts']
+        @pool.columns_hash['posts']
+
+        @pool.clear_cache!
+
+        assert_equal 0, @pool.columns.size
+        assert_equal 0, @pool.columns_hash.size
+      end
+
+      def test_primary_key
+        assert_equal 'id', @pool.primary_keys['posts']
+      end
+
+      def test_primary_key_for_non_existent_table
+        assert_equal 'id', @pool.primary_keys['omgponies']
+      end
+
+      def test_primary_key_is_set_on_columns
+        posts_columns = @pool.columns_hash['posts']
+        assert posts_columns['id'].primary
+
+        (posts_columns.keys - ['id']).each do |key|
+          assert !posts_columns[key].primary
+        end
+      end
+
       def test_clear_stale_cached_connections!
         pool = ConnectionPool.new ActiveRecord::Base.connection_pool.spec
 
@@ -55,6 +107,26 @@ module ActiveRecord
         end.join()
 
       end
+
+      def test_automatic_reconnect=
+        pool = ConnectionPool.new ActiveRecord::Base.connection_pool.spec
+        assert pool.automatic_reconnect
+        assert pool.connection
+
+        pool.disconnect!
+        assert pool.connection
+
+        pool.disconnect!
+        pool.automatic_reconnect = false
+
+        assert_raises(ConnectionNotEstablished) do
+          pool.connection
+        end
+
+        assert_raises(ConnectionNotEstablished) do
+          pool.with_connection
+        end
+      end
     end
   end
 end
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 31e4981a1d..c35590b84b 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -982,7 +982,7 @@ class FinderTest < ActiveRecord::TestCase
 
   def test_select_rows
     assert_equal(
-      [["1", nil, nil, "37signals"],
+      [["1", "1", nil, "37signals"],
        ["2", "1", "2", "Summit"],
        ["3", "1", "1", "Microsoft"]],
       Company.connection.select_rows("SELECT id, firm_id, client_of, name FROM companies WHERE id IN (1,2,3) ORDER BY id").map! {|i| i.map! {|j| j.to_s unless j.nil?}})
diff --git a/activerecord/test/cases/fixtures_test.rb b/activerecord/test/cases/fixtures_test.rb
index 9ce163a00f..ee51692f93 100644
--- a/activerecord/test/cases/fixtures_test.rb
+++ b/activerecord/test/cases/fixtures_test.rb
@@ -13,6 +13,7 @@ require 'models/category'
 require 'models/parrot'
 require 'models/pirate'
 require 'models/treasure'
+require 'models/traffic_light'
 require 'models/matey'
 require 'models/ship'
 require 'models/book'
@@ -24,7 +25,7 @@ class FixturesTest < ActiveRecord::TestCase
   self.use_instantiated_fixtures = true
   self.use_transactional_fixtures = false
 
-  fixtures :topics, :developers, :accounts, :tasks, :categories, :funny_jokes, :binaries
+  fixtures :topics, :developers, :accounts, :tasks, :categories, :funny_jokes, :binaries, :traffic_lights
 
   FIXTURES = %w( accounts binaries companies customers
                  developers developers_projects entrants
@@ -34,7 +35,7 @@ class FixturesTest < ActiveRecord::TestCase
   def test_clean_fixtures
     FIXTURES.each do |name|
       fixtures = nil
-      assert_nothing_raised { fixtures = create_fixtures(name) }
+      assert_nothing_raised { fixtures = create_fixtures(name).first }
       assert_kind_of(Fixtures, fixtures)
       fixtures.each { |_name, fixture|
         fixture.each { |key, value|
@@ -52,7 +53,7 @@ class FixturesTest < ActiveRecord::TestCase
   end
 
   def test_attributes
-    topics = create_fixtures("topics")
+    topics = create_fixtures("topics").first
     assert_equal("The First Topic", topics["first"]["title"])
     assert_nil(topics["second"]["author_email_address"])
   end
@@ -126,7 +127,7 @@ class FixturesTest < ActiveRecord::TestCase
   end
 
   def test_instantiation
-    topics = create_fixtures("topics")
+    topics = create_fixtures("topics").first
     assert_kind_of Topic, topics["first"].find
   end
 
@@ -204,6 +205,10 @@ class FixturesTest < ActiveRecord::TestCase
     data.freeze
     assert_equal data, @flowers.data
   end
+
+  def test_serialized_fixtures
+    assert_equal ["Green", "Red", "Orange"], traffic_lights(:uk).state
+  end
 end
 
 if Account.connection.respond_to?(:reset_pk_sequence!)
@@ -240,7 +245,7 @@ if Account.connection.respond_to?(:reset_pk_sequence!)
 
     def test_create_fixtures_resets_sequences_when_not_cached
       @instances.each do |instance|
-        max_id = create_fixtures(instance.class.table_name).inject(0) do |_max_id, (_, fixture)|
+        max_id = create_fixtures(instance.class.table_name).first.fixtures.inject(0) do |_max_id, (_, fixture)|
           fixture_id = fixture['id'].to_i
           fixture_id > _max_id ? fixture_id : _max_id
         end
@@ -504,7 +509,7 @@ class FasterFixturesTest < ActiveRecord::TestCase
   fixtures :categories, :authors
 
   def load_extra_fixture(name)
-    fixture = create_fixtures(name)
+    fixture = create_fixtures(name).first
     assert fixture.is_a?(Fixtures)
     @loaded_fixtures[fixture.table_name] = fixture
   end
diff --git a/activerecord/test/cases/habtm_destroy_order_test.rb b/activerecord/test/cases/habtm_destroy_order_test.rb
new file mode 100644
index 0000000000..15598392e2
--- /dev/null
+++ b/activerecord/test/cases/habtm_destroy_order_test.rb
@@ -0,0 +1,17 @@
+require "cases/helper"
+require "models/lesson"
+require "models/student"
+
+class HabtmDestroyOrderTest < ActiveRecord::TestCase
+  test "may not delete a lesson with students" do
+    sicp = Lesson.new(:name => "SICP")
+    ben = Student.new(:name => "Ben Bitdiddle")
+    sicp.students << ben
+    sicp.save!
+    assert_raises LessonError do
+      assert_no_difference('Lesson.count') do
+        sicp.destroy
+      end
+    end
+  end
+end
diff --git a/activerecord/test/cases/helper.rb b/activerecord/test/cases/helper.rb
index 942a5c048e..ad0430a92f 100644
--- a/activerecord/test/cases/helper.rb
+++ b/activerecord/test/cases/helper.rb
@@ -36,6 +36,15 @@ def current_adapter?(*types)
   end
 end
 
+def in_memory_db?
+  current_adapter?(:SQLiteAdapter) &&
+  ActiveRecord::Base.connection_pool.spec.config[:database] == ":memory:"
+end
+
+def supports_savepoints?
+  ActiveRecord::Base.connection.supports_savepoints?
+end
+
 def with_env_tz(new_tz = 'US/Eastern')
   old_tz, ENV['TZ'] = ENV['TZ'], new_tz
   yield
@@ -50,42 +59,31 @@ ensure
   ActiveRecord::Base.default_timezone = old_zone
 end
 
-ActiveRecord::Base.connection.class.class_eval do
-  IGNORED_SQL = [/^PRAGMA/, /^SELECT currval/, /^SELECT CAST/, /^SELECT @@IDENTITY/, /^SELECT @@ROWCOUNT/, /^SAVEPOINT/, /^ROLLBACK TO SAVEPOINT/, /^RELEASE SAVEPOINT/, /SHOW FIELDS/]
+module ActiveRecord
+  class SQLCounter
+    IGNORED_SQL = [/^PRAGMA (?!(table_info))/, /^SELECT currval/, /^SELECT CAST/, /^SELECT @@IDENTITY/, /^SELECT @@ROWCOUNT/, /^SAVEPOINT/, /^ROLLBACK TO SAVEPOINT/, /^RELEASE SAVEPOINT/, /^SHOW max_identifier_length/]
 
-  # FIXME: this needs to be refactored so specific database can add their own
-  # ignored SQL.  This ignored SQL is for Oracle.
-  IGNORED_SQL.concat [/^select .*nextval/i, /^SAVEPOINT/, /^ROLLBACK TO/, /^\s*select .* from ((all|user)_tab_columns|(all|user)_triggers|(all|user)_constraints)/im]
+    # FIXME: this needs to be refactored so specific database can add their own
+    # ignored SQL.  This ignored SQL is for Oracle.
+    IGNORED_SQL.concat [/^select .*nextval/i, /^SAVEPOINT/, /^ROLLBACK TO/, /^\s*select .* from all_triggers/im]
 
-  def execute_with_query_record(sql, name = nil, &block)
-    $queries_executed ||= []
-    $queries_executed << sql unless IGNORED_SQL.any? { |r| sql =~ r }
-    execute_without_query_record(sql, name, &block)
-  end
+    def initialize
+      $queries_executed = []
+    end
 
-  alias_method_chain :execute, :query_record
+    def call(name, start, finish, message_id, values)
+      sql = values[:sql]
 
-  def exec_query_with_query_record(sql, name = nil, binds = [], &block)
-    $queries_executed ||= []
-    $queries_executed << sql unless IGNORED_SQL.any? { |r| sql =~ r }
-    exec_query_without_query_record(sql, name, binds, &block)
+      # FIXME: this seems bad. we should probably have a better way to indicate
+      # the query was cached
+      unless 'CACHE' == values[:name]
+        $queries_executed << sql unless IGNORED_SQL.any? { |r| sql =~ r }
+      end
+    end
   end
-
-  alias_method_chain :exec_query, :query_record
+  ActiveSupport::Notifications.subscribe('sql.active_record', SQLCounter.new)
 end
 
-ActiveRecord::Base.connection.class.class_eval {
-  attr_accessor :column_calls
-
-  def columns_with_calls(*args)
-    @column_calls ||= 0
-    @column_calls += 1
-    columns_without_calls(*args)
-  end
-
-  alias_method_chain :columns, :calls
-}
-
 unless ENV['FIXTURE_DEBUG']
   module ActiveRecord::TestFixtures::ClassMethods
     def try_to_load_dependency_with_silence(*args)
@@ -106,15 +104,15 @@ class ActiveSupport::TestCase
   self.use_transactional_fixtures = true
 
   def create_fixtures(*table_names, &block)
-    Fixtures.create_fixtures(ActiveSupport::TestCase.fixture_path, table_names, {}, &block)
+    Fixtures.create_fixtures(ActiveSupport::TestCase.fixture_path, table_names, fixture_class_names, &block)
   end
 end
 
-# silence verbose schema loading
-original_stdout = $stdout
-$stdout = StringIO.new
+def load_schema
+  # silence verbose schema loading
+  original_stdout = $stdout
+  $stdout = StringIO.new
 
-begin
   adapter_name = ActiveRecord::Base.connection.adapter_name.downcase
   adapter_specific_schema_file = SCHEMA_ROOT + "/#{adapter_name}_specific_schema.rb"
 
@@ -127,6 +125,8 @@ ensure
   $stdout = original_stdout
 end
 
+load_schema
+
 class << Time
   unless method_defined? :now_before_time_travel
     alias_method :now_before_time_travel, :now
@@ -143,4 +143,3 @@ class << Time
     @now = nil
   end
 end
-
diff --git a/activerecord/test/cases/inheritance_test.rb b/activerecord/test/cases/inheritance_test.rb
index c3da9cdf53..680d4ca5dd 100644
--- a/activerecord/test/cases/inheritance_test.rb
+++ b/activerecord/test/cases/inheritance_test.rb
@@ -203,12 +203,12 @@ class InheritanceTest < ActiveRecord::TestCase
 
   def test_eager_load_belongs_to_something_inherited
     account = Account.find(1, :include => :firm)
-    assert_not_nil account.instance_variable_get("@firm"), "nil proves eager load failed"
+    assert account.association_cache.key?(:firm), "nil proves eager load failed"
   end
 
   def test_eager_load_belongs_to_primary_key_quoting
     con = Account.connection
-    assert_sql(/\(#{con.quote_table_name('companies')}.#{con.quote_column_name('id')} = 1\)/) do
+    assert_sql(/#{con.quote_table_name('companies')}.#{con.quote_column_name('id')} = 1/) do
       Account.find(1, :include => :firm)
     end
   end
@@ -219,6 +219,10 @@ class InheritanceTest < ActiveRecord::TestCase
     switch_to_default_inheritance_column
   end
 
+  def test_inherits_custom_primary_key
+    assert_equal Subscriber.primary_key, SpecialSubscriber.primary_key
+  end
+
   def test_inheritance_without_mapping
     assert_kind_of SpecialSubscriber, SpecialSubscriber.find("webster132")
     assert_nothing_raised { s = SpecialSubscriber.new("name" => "And breaaaaathe!"); s.id = 'roger'; s.save }
diff --git a/activerecord/test/cases/lifecycle_test.rb b/activerecord/test/cases/lifecycle_test.rb
index b8c3ffb9cb..0558deb71b 100644
--- a/activerecord/test/cases/lifecycle_test.rb
+++ b/activerecord/test/cases/lifecycle_test.rb
@@ -101,9 +101,10 @@ class LifecycleTest < ActiveRecord::TestCase
   fixtures :topics, :developers, :minimalistics
 
   def test_before_destroy
-    original_count = Topic.count
-    (topic_to_be_destroyed = Topic.find(1)).destroy
-    assert_equal original_count - (1 + topic_to_be_destroyed.replies.size), Topic.count
+    topic = Topic.find(1)
+    assert_difference 'Topic.count', -(1 + topic.replies.size) do
+      topic.destroy
+    end
   end
 
   def test_auto_observer
diff --git a/activerecord/test/cases/locking_test.rb b/activerecord/test/cases/locking_test.rb
index f9678cb0c5..636a709924 100644
--- a/activerecord/test/cases/locking_test.rb
+++ b/activerecord/test/cases/locking_test.rb
@@ -1,6 +1,7 @@
 require 'thread'
 require "cases/helper"
 require 'models/person'
+require 'models/job'
 require 'models/reader'
 require 'models/legacy_thing'
 require 'models/reference'
@@ -19,11 +20,6 @@ end
 class OptimisticLockingTest < ActiveRecord::TestCase
   fixtures :people, :legacy_things, :references
 
-  # need to disable transactional fixtures, because otherwise the sqlite3
-  # adapter (at least) chokes when we try and change the schema in the middle
-  # of a test (see test_increment_counter_*).
-  self.use_transactional_fixtures = false
-
   def test_lock_existing
     p1 = Person.find(1)
     p2 = Person.find(1)
@@ -103,6 +99,14 @@ class OptimisticLockingTest < ActiveRecord::TestCase
     assert_equal 1, p1.lock_version
   end
 
+  def test_touch_existing_lock
+    p1 = Person.find(1)
+    assert_equal 0, p1.lock_version
+
+    p1.touch
+    assert_equal 1, p1.lock_version
+  end
+
 
   def test_lock_column_name_existing
     t1 = LegacyThing.find(1)
@@ -152,6 +156,33 @@ class OptimisticLockingTest < ActiveRecord::TestCase
     assert_equal "unchangeable name", p.first_name
   end
 
+  def test_quote_table_name
+    ref = references(:michael_magician)
+    ref.favourite = !ref.favourite
+    assert ref.save
+  end
+
+  # Useful for partial updates, don't only update the lock_version if there
+  # is nothing else being updated.
+  def test_update_without_attributes_does_not_only_update_lock_version
+    assert_nothing_raised do
+      p1 = Person.create!(:first_name => 'anika')
+      lock_version = p1.lock_version
+      p1.save
+      p1.reload
+      assert_equal lock_version, p1.lock_version
+    end
+  end
+end
+
+class OptimisticLockingWithSchemaChangeTest < ActiveRecord::TestCase
+  fixtures :people, :legacy_things, :references
+
+  # need to disable transactional fixtures, because otherwise the sqlite3
+  # adapter (at least) chokes when we try and change the schema in the middle
+  # of a test (see test_increment_counter_*).
+  self.use_transactional_fixtures = false
+
   { :lock_version => Person, :custom_lock_version => LegacyThing }.each do |name, model|
     define_method("test_increment_counter_updates_#{name}") do
       counter_test model, 1 do |id|
@@ -198,24 +229,6 @@ class OptimisticLockingTest < ActiveRecord::TestCase
     assert_raises(ActiveRecord::RecordNotFound) { LegacyThing.find(t.id) }
   end
 
-  def test_quote_table_name
-    ref = references(:michael_magician)
-    ref.favourite = !ref.favourite
-    assert ref.save
-  end
-
-  # Useful for partial updates, don't only update the lock_version if there
-  # is nothing else being updated.
-  def test_update_without_attributes_does_not_only_update_lock_version
-    assert_nothing_raised do
-      p1 = Person.create!(:first_name => 'anika')
-      lock_version = p1.lock_version
-      p1.save
-      p1.reload
-      assert_equal lock_version, p1.lock_version
-    end
-  end
-
   private
 
     def add_counter_column_to(model, col='test_count')
@@ -252,7 +265,7 @@ end
 
 # TODO: The Sybase, and OpenBase adapters currently have no support for pessimistic locking
 
-unless current_adapter?(:SybaseAdapter, :OpenBaseAdapter)
+unless current_adapter?(:SybaseAdapter, :OpenBaseAdapter) || in_memory_db?
   class PessimisticLockingTest < ActiveRecord::TestCase
     self.use_transactional_fixtures = false
     fixtures :people, :readers
diff --git a/activerecord/test/cases/method_scoping_test.rb b/activerecord/test/cases/method_scoping_test.rb
index 0ffd0e2ab3..7e8383da9e 100644
--- a/activerecord/test/cases/method_scoping_test.rb
+++ b/activerecord/test/cases/method_scoping_test.rb
@@ -14,7 +14,7 @@ class MethodScopingTest < ActiveRecord::TestCase
 
   def test_set_conditions
     Developer.send(:with_scope, :find => { :conditions => 'just a test...' }) do
-      assert_equal '(just a test...)', Developer.scoped.arel.send(:where_clauses).join(' AND ')
+      assert_match '(just a test...)', Developer.scoped.arel.to_sql
     end
   end
 
@@ -227,7 +227,7 @@ class MethodScopingTest < ActiveRecord::TestCase
   end
 
   def test_scoped_create_with_join_and_merge
-    (Comment.where(:body => "but Who's Buying?").joins(:post) & Post.where(:body => 'Peace Sells...')).with_scope do
+    Comment.where(:body => "but Who's Buying?").joins(:post).merge(Post.where(:body => 'Peace Sells...')).with_scope do
       assert_equal({:body => "but Who's Buying?"}, Comment.scoped.scope_for_create)
     end
   end
@@ -275,7 +275,7 @@ class NestedScopingTest < ActiveRecord::TestCase
     Developer.send(:with_scope, :find => { :conditions => 'salary = 80000' }) do
       Developer.send(:with_scope, :find => { :limit => 10 }) do
         devs = Developer.scoped
-        assert_equal '(salary = 80000)', devs.arel.send(:where_clauses).join(' AND ')
+        assert_match '(salary = 80000)', devs.arel.to_sql
         assert_equal 10, devs.taken
       end
     end
@@ -309,7 +309,7 @@ class NestedScopingTest < ActiveRecord::TestCase
     Developer.send(:with_scope, :find => { :conditions => "name = 'David'" }) do
       Developer.send(:with_scope, :find => { :conditions => 'salary = 80000' }) do
         devs = Developer.scoped
-        assert_equal "(name = 'David') AND (salary = 80000)", devs.arel.send(:where_clauses).join(' AND ')
+        assert_match "(name = 'David') AND (salary = 80000)", devs.arel.to_sql
         assert_equal(1, Developer.count)
       end
       Developer.send(:with_scope, :find => { :conditions => "name = 'Maiha'" }) do
@@ -322,7 +322,7 @@ class NestedScopingTest < ActiveRecord::TestCase
     Developer.send(:with_scope, :find => { :conditions => 'salary = 80000', :limit => 10 }) do
       Developer.send(:with_scope, :find => { :conditions => "name = 'David'" }) do
         devs = Developer.scoped
-        assert_equal "(salary = 80000) AND (name = 'David')", devs.arel.send(:where_clauses).join(' AND ')
+        assert_match "(salary = 80000) AND (name = 'David')", devs.arel.to_sql
         assert_equal 10, devs.taken
       end
     end
diff --git a/activerecord/test/cases/migration/command_recorder_test.rb b/activerecord/test/cases/migration/command_recorder_test.rb
index ea2292dda5..ae531ebb4c 100644
--- a/activerecord/test/cases/migration/command_recorder_test.rb
+++ b/activerecord/test/cases/migration/command_recorder_test.rb
@@ -16,7 +16,7 @@ module ActiveRecord
 
       def test_send_calls_super
         assert_raises(NoMethodError) do
-          @recorder.send(:create_table, :horses)
+          @recorder.send(:non_existing_method, :horses)
         end
       end
 
diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 1a65045ded..9d7c49768b 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -14,7 +14,7 @@ if ActiveRecord::Base.connection.supports_migrations?
   class Reminder < ActiveRecord::Base; end
 
   class ActiveRecord::Migration
-    class <<self
+    class << self
       attr_accessor :message_count
     end
 
@@ -1923,6 +1923,149 @@ if ActiveRecord::Base.connection.supports_migrations?
     end
   end
 
+  if ActiveRecord::Base.connection.supports_bulk_alter?
+    class BulkAlterTableMigrationsTest < ActiveRecord::TestCase
+      def setup
+        @connection = Person.connection
+        @connection.create_table(:delete_me, :force => true) {|t| }
+      end
+
+      def teardown
+        Person.connection.drop_table(:delete_me) rescue nil
+      end
+
+      def test_adding_multiple_columns
+        assert_queries(1) do
+          with_bulk_change_table do |t|
+            t.column :name, :string
+            t.string :qualification, :experience
+            t.integer :age, :default => 0
+            t.date :birthdate
+            t.timestamps
+          end
+        end
+
+        assert_equal 8, columns.size
+        [:name, :qualification, :experience].each {|s| assert_equal :string, column(s).type }
+        assert_equal 0, column(:age).default
+      end
+
+      def test_removing_columns
+        with_bulk_change_table do |t|
+          t.string :qualification, :experience
+        end
+
+        [:qualification, :experience].each {|c| assert column(c) }
+
+        assert_queries(1) do
+          with_bulk_change_table do |t|
+            t.remove :qualification, :experience
+            t.string :qualification_experience
+          end
+        end
+
+        [:qualification, :experience].each {|c| assert ! column(c) }
+        assert column(:qualification_experience)
+      end
+
+      def test_adding_indexes
+        with_bulk_change_table do |t|
+          t.string :username
+          t.string :name
+          t.integer :age
+        end
+
+        # Adding an index fires a query everytime to check if an index already exists or not
+        assert_queries(3) do
+          with_bulk_change_table do |t|
+            t.index :username, :unique => true, :name => :awesome_username_index
+            t.index [:name, :age]
+          end
+        end
+
+        assert_equal 2, indexes.size
+
+        name_age_index = index(:index_delete_me_on_name_and_age)
+        assert_equal ['name', 'age'].sort, name_age_index.columns.sort
+        assert ! name_age_index.unique
+
+        assert index(:awesome_username_index).unique
+      end
+
+      def test_removing_index
+        with_bulk_change_table do |t|
+          t.string :name
+          t.index :name
+        end
+
+        assert index(:index_delete_me_on_name)
+
+        assert_queries(3) do
+          with_bulk_change_table do |t|
+            t.remove_index :name
+            t.index :name, :name => :new_name_index, :unique => true
+          end
+        end
+
+        assert ! index(:index_delete_me_on_name)
+
+        new_name_index = index(:new_name_index)
+        assert new_name_index.unique
+      end
+
+      def test_changing_columns
+        with_bulk_change_table do |t|
+          t.string :name
+          t.date :birthdate
+        end
+
+        assert ! column(:name).default
+        assert_equal :date, column(:birthdate).type
+
+        # One query for columns (delete_me table)
+        # One query for primary key (delete_me table)
+        # One query to do the bulk change
+        assert_queries(3) do
+          with_bulk_change_table do |t|
+            t.change :name, :string, :default => 'NONAME'
+            t.change :birthdate, :datetime
+          end
+        end
+
+        assert_equal 'NONAME', column(:name).default
+        assert_equal :datetime, column(:birthdate).type
+      end
+
+      protected
+
+      def with_bulk_change_table
+        # Reset columns/indexes cache as we're changing the table
+        @columns = @indexes = nil
+
+        Person.connection.change_table(:delete_me, :bulk => true) do |t|
+          yield t
+        end
+      end
+
+      def column(name)
+        columns.detect {|c| c.name == name.to_s }
+      end
+
+      def columns
+        @columns ||= Person.connection.columns('delete_me')
+      end
+
+      def index(name)
+        indexes.detect {|i| i.name == name.to_s }
+      end
+
+      def indexes
+        @indexes ||= Person.connection.indexes('delete_me')
+      end
+    end # AlterTableMigrationsTest
+
+  end
+
   class CopyMigrationsTest < ActiveRecord::TestCase
     def setup
     end
@@ -2083,4 +2226,3 @@ if ActiveRecord::Base.connection.supports_migrations?
     end
   end
 end
-
diff --git a/activerecord/test/cases/modules_test.rb b/activerecord/test/cases/modules_test.rb
index 14870cb0e2..a2041af16a 100644
--- a/activerecord/test/cases/modules_test.rb
+++ b/activerecord/test/cases/modules_test.rb
@@ -49,7 +49,6 @@ class ModulesTest < ActiveRecord::TestCase
 
   def test_find_account_and_include_company
     account = MyApplication::Billing::Account.find(1, :include => :firm)
-    assert_kind_of MyApplication::Business::Firm, account.instance_variable_get('@firm')
     assert_kind_of MyApplication::Business::Firm, account.firm
   end
 
diff --git a/activerecord/test/cases/nested_attributes_test.rb b/activerecord/test/cases/nested_attributes_test.rb
index ffcc7a081a..d1afe7376a 100644
--- a/activerecord/test/cases/nested_attributes_test.rb
+++ b/activerecord/test/cases/nested_attributes_test.rb
@@ -147,6 +147,15 @@ class TestNestedAttributesInGeneral < ActiveRecord::TestCase
     pirate.ship_attributes = { :id => "" }
     assert_nothing_raised(ActiveRecord::RecordNotFound) { pirate.save! }
   end
+
+  def test_first_and_array_index_zero_methods_return_the_same_value_when_nested_attributes_are_set_to_update_existing_record
+    Man.accepts_nested_attributes_for(:interests)
+    man = Man.create(:name => "John")
+    interest = man.interests.create :topic => 'gardning'
+    man = Man.find man.id
+    man.interests_attributes = [{:id => interest.id, :topic => 'gardening'}]
+    assert_equal man.interests.first.topic, man.interests[0].topic
+  end  
 end
 
 class TestNestedAttributesOnAHasOneAssociation < ActiveRecord::TestCase
@@ -298,7 +307,7 @@ class TestNestedAttributesOnAHasOneAssociation < ActiveRecord::TestCase
 
   def test_should_create_new_model_when_nothing_is_there_and_update_only_is_true
     @ship.delete
-    
+
     @pirate.reload.update_attributes(:update_only_ship_attributes => { :name => 'Mayflower' })
 
     assert_not_nil @pirate.ship
@@ -451,7 +460,7 @@ class TestNestedAttributesOnABelongsToAssociation < ActiveRecord::TestCase
 
   def test_should_not_destroy_the_associated_model_until_the_parent_is_saved
     pirate = @ship.pirate
-    
+
     @ship.attributes = { :pirate_attributes => { :id => pirate.id, '_destroy' => true } }
     assert_nothing_raised(ActiveRecord::RecordNotFound) { Pirate.find(pirate.id) }
     @ship.save
@@ -859,7 +868,7 @@ class TestNestedAttributesWithNonStandardPrimaryKeys < ActiveRecord::TestCase
 end
 
 class TestHasOneAutosaveAssociationWhichItselfHasAutosaveAssociations < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @pirate = Pirate.create!(:catchphrase => "My baby takes tha mornin' train!")
@@ -899,7 +908,7 @@ class TestHasOneAutosaveAssociationWhichItselfHasAutosaveAssociations < ActiveRe
 end
 
 class TestHasManyAutosaveAssociationWhichItselfHasAutosaveAssociations < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @ship = Ship.create!(:name => "The good ship Dollypop")
diff --git a/activerecord/test/cases/pooled_connections_test.rb b/activerecord/test/cases/pooled_connections_test.rb
index de5fa140ba..6269437b14 100644
--- a/activerecord/test/cases/pooled_connections_test.rb
+++ b/activerecord/test/cases/pooled_connections_test.rb
@@ -137,4 +137,4 @@ class PooledConnectionsTest < ActiveRecord::TestCase
   def add_record(name)
     ActiveRecord::Base.connection_pool.with_connection { Project.create! :name => name }
   end
-end unless %w(FrontBase).include? ActiveRecord::Base.connection.adapter_name
+end unless current_adapter?(:FrontBase) || in_memory_db?
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 33916c4e46..53aefc7b58 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -63,7 +63,7 @@ class QueryCacheTest < ActiveRecord::TestCase
       # Oracle adapter returns count() as Fixnum or Float
       if current_adapter?(:OracleAdapter)
         assert_kind_of Numeric, Task.connection.select_value("SELECT count(*) AS count_all FROM tasks")
-      elsif current_adapter?(:SQLite3Adapter) && SQLite3::Version::VERSION > '1.2.5' || current_adapter?(:Mysql2Adapter) || current_adapter?(:MysqlAdapter)
+      elsif current_adapter?(:SQLite3Adapter) && SQLite3::VERSION > '1.2.5' || current_adapter?(:Mysql2Adapter) || current_adapter?(:MysqlAdapter)
         # Future versions of the sqlite3 adapter will return numeric
         assert_instance_of Fixnum,
          Task.connection.select_value("SELECT count(*) AS count_all FROM tasks")
diff --git a/activerecord/test/cases/quoting_test.rb b/activerecord/test/cases/quoting_test.rb
index 2ef5b5a800..b87fb51d97 100644
--- a/activerecord/test/cases/quoting_test.rb
+++ b/activerecord/test/cases/quoting_test.rb
@@ -154,13 +154,13 @@ module ActiveRecord
       end
 
       def test_crazy_object
-        crazy = Class.new { def to_s; 'lol' end }.new
+        crazy = Class.new { def to_yaml; 'lol' end }.new
         assert_equal "'lol'", @quoter.quote(crazy, nil)
         assert_equal "'lol'", @quoter.quote(crazy, Object.new)
       end
 
       def test_crazy_object_calls_quote_string
-        crazy = Class.new { def to_s; 'lo\l' end }.new
+        crazy = Class.new { def to_yaml; 'lo\l' end }.new
         assert_equal "'lo\\\\l'", @quoter.quote(crazy, nil)
         assert_equal "'lo\\\\l'", @quoter.quote(crazy, Object.new)
       end
diff --git a/activerecord/test/cases/readonly_test.rb b/activerecord/test/cases/readonly_test.rb
index 98011f40a4..e21109baae 100644
--- a/activerecord/test/cases/readonly_test.rb
+++ b/activerecord/test/cases/readonly_test.rb
@@ -6,13 +6,8 @@ require 'models/project'
 require 'models/reader'
 require 'models/person'
 
-# Dummy class methods to test implicit association scoping.
-def Comment.foo() find :first end
-def Project.foo() find :first end
-
-
 class ReadOnlyTest < ActiveRecord::TestCase
-  fixtures :posts, :comments, :developers, :projects, :developers_projects
+  fixtures :posts, :comments, :developers, :projects, :developers_projects, :people, :readers
 
   def test_cant_save_readonly_record
     dev = Developer.find(1)
@@ -49,15 +44,6 @@ class ReadOnlyTest < ActiveRecord::TestCase
     Developer.joins(', projects').readonly(false).each { |d| assert !d.readonly? }
   end
 
-
-  def test_habtm_find_readonly
-    dev = Developer.find(1)
-    assert !dev.projects.empty?
-    assert dev.projects.all?(&:readonly?)
-    assert dev.projects.find(:all).all?(&:readonly?)
-    assert dev.projects.readonly(true).all?(&:readonly?)
-  end
-
   def test_has_many_find_readonly
     post = Post.find(1)
     assert !post.comments.empty?
@@ -71,6 +57,18 @@ class ReadOnlyTest < ActiveRecord::TestCase
     assert !people.any?(&:readonly?)
   end
 
+  def test_has_many_with_through_is_not_implicitly_marked_readonly_while_finding_by_id
+    assert !posts(:welcome).people.find(1).readonly?
+  end
+
+  def test_has_many_with_through_is_not_implicitly_marked_readonly_while_finding_first
+    assert !posts(:welcome).people.first.readonly?
+  end
+
+  def test_has_many_with_through_is_not_implicitly_marked_readonly_while_finding_last
+    assert !posts(:welcome).people.last.readonly?
+  end
+
   def test_readonly_scoping
     Post.send(:with_scope, :find => { :conditions => '1=1' }) do
       assert !Post.find(1).readonly?
@@ -102,7 +100,13 @@ class ReadOnlyTest < ActiveRecord::TestCase
   end
 
   def test_association_collection_method_missing_scoping_not_readonly
-    assert !Developer.find(1).projects.foo.readonly?
-    assert !Post.find(1).comments.foo.readonly?
+    developer = Developer.find(1)
+    project   = Post.find(1)
+
+    assert !developer.projects.all_as_method.first.readonly?
+    assert !developer.projects.all_as_scope.first.readonly?
+
+    assert !project.comments.all_as_method.first.readonly?
+    assert !project.comments.all_as_scope.first.readonly?
   end
 end
diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb
index 912e3c47bb..eb580928ba 100644
--- a/activerecord/test/cases/reflection_test.rb
+++ b/activerecord/test/cases/reflection_test.rb
@@ -7,6 +7,10 @@ require 'models/subscriber'
 require 'models/ship'
 require 'models/pirate'
 require 'models/price_estimate'
+require 'models/tagging'
+require 'models/author'
+require 'models/post'
+require 'models/sponsor'
 
 class ReflectionTest < ActiveRecord::TestCase
   include ActiveRecord::Reflection
@@ -126,11 +130,11 @@ class ReflectionTest < ActiveRecord::TestCase
 
   def test_belongs_to_inferred_foreign_key_from_assoc_name
     Company.belongs_to :foo
-    assert_equal "foo_id", Company.reflect_on_association(:foo).primary_key_name
+    assert_equal "foo_id", Company.reflect_on_association(:foo).foreign_key
     Company.belongs_to :bar, :class_name => "Xyzzy"
-    assert_equal "bar_id", Company.reflect_on_association(:bar).primary_key_name
+    assert_equal "bar_id", Company.reflect_on_association(:bar).foreign_key
     Company.belongs_to :baz, :class_name => "Xyzzy", :foreign_key => "xyzzy_id"
-    assert_equal "xyzzy_id", Company.reflect_on_association(:baz).primary_key_name
+    assert_equal "xyzzy_id", Company.reflect_on_association(:baz).foreign_key
   end
 
   def test_association_reflection_in_modules
@@ -177,8 +181,8 @@ class ReflectionTest < ActiveRecord::TestCase
 
   def test_reflection_of_all_associations
     # FIXME these assertions bust a lot
-    assert_equal 37, Firm.reflect_on_all_associations.size
-    assert_equal 27, Firm.reflect_on_all_associations(:has_many).size
+    assert_equal 36, Firm.reflect_on_all_associations.size
+    assert_equal 26, Firm.reflect_on_all_associations(:has_many).size
     assert_equal 10, Firm.reflect_on_all_associations(:has_one).size
     assert_equal 0, Firm.reflect_on_all_associations(:belongs_to).size
   end
@@ -191,11 +195,22 @@ class ReflectionTest < ActiveRecord::TestCase
     assert_kind_of ThroughReflection, Subscriber.reflect_on_association(:books)
   end
 
+  def test_association_primary_key
+    assert_equal "id", Author.reflect_on_association(:posts).association_primary_key.to_s
+    assert_equal "name", Author.reflect_on_association(:essay).association_primary_key.to_s
+    assert_equal "id", Tagging.reflect_on_association(:taggable).association_primary_key.to_s
+  end
+
   def test_active_record_primary_key
     assert_equal "nick", Subscriber.reflect_on_association(:subscriptions).active_record_primary_key.to_s
     assert_equal "name", Author.reflect_on_association(:essay).active_record_primary_key.to_s
   end
 
+  def test_foreign_type
+    assert_equal "sponsorable_type", Sponsor.reflect_on_association(:sponsorable).foreign_type.to_s
+    assert_equal "sponsorable_type", Sponsor.reflect_on_association(:thing).foreign_type.to_s
+  end
+
   def test_collection_association
     assert Pirate.reflect_on_association(:birds).collection?
     assert Pirate.reflect_on_association(:parrots).collection?
@@ -233,6 +248,18 @@ class ReflectionTest < ActiveRecord::TestCase
     assert !AssociationReflection.new(:has_and_belongs_to_many, :clients, { :autosave => true, :validate => false }, Firm).validate?
   end
 
+  def test_foreign_key
+    assert_equal "author_id", Author.reflect_on_association(:posts).foreign_key.to_s
+    assert_equal "category_id", Post.reflect_on_association(:categorizations).foreign_key.to_s
+  end
+
+  def test_primary_key_name
+    assert_deprecated do
+      assert_equal "author_id", Author.reflect_on_association(:posts).primary_key_name.to_s
+      assert_equal "category_id", Post.reflect_on_association(:categorizations).primary_key_name.to_s
+    end
+  end
+
   private
     def assert_reflection(klass, association, options)
       assert reflection = klass.reflect_on_association(association)
diff --git a/activerecord/test/cases/relation_scoping_test.rb b/activerecord/test/cases/relation_scoping_test.rb
index f113a9c516..cda2850b02 100644
--- a/activerecord/test/cases/relation_scoping_test.rb
+++ b/activerecord/test/cases/relation_scoping_test.rb
@@ -152,7 +152,7 @@ class NestedRelationScopingTest < ActiveRecord::TestCase
     Developer.where('salary = 80000').scoping do
       Developer.limit(10).scoping do
         devs = Developer.scoped
-        assert_equal '(salary = 80000)', devs.arel.send(:where_clauses).join(' AND ')
+        assert_match '(salary = 80000)', devs.arel.to_sql
         assert_equal 10, devs.taken
       end
     end
@@ -259,7 +259,8 @@ class HasManyScopingTest< ActiveRecord::TestCase
   end
 
   def test_should_default_scope_on_associations_is_overriden_by_association_conditions
-    assert_equal [], people(:michael).fixed_bad_references
+    reference = references(:michael_unicyclist).becomes(BadReference)
+    assert_equal [reference], people(:michael).fixed_bad_references
   end
 
   def test_should_maintain_default_scope_on_eager_loaded_associations
@@ -485,4 +486,21 @@ class DefaultScopingTest < ActiveRecord::TestCase
     posts_offset_limit = Post.offset(2).limit(3)
     assert_equal posts_limit_offset, posts_offset_limit
   end
+
+  def test_create_with_merge
+    aaron = PoorDeveloperCalledJamis.create_with(:name => 'foo', :salary => 20).merge(
+              PoorDeveloperCalledJamis.create_with(:name => 'Aaron')).new
+    assert_equal 20, aaron.salary
+    assert_equal 'Aaron', aaron.name
+
+    aaron = PoorDeveloperCalledJamis.create_with(:name => 'foo', :salary => 20).
+                                     create_with(:name => 'Aaron').new
+    assert_equal 20, aaron.salary
+    assert_equal 'Aaron', aaron.name
+  end
+
+  def test_create_with_reset
+    jamis = PoorDeveloperCalledJamis.create_with(:name => 'Aaron').create_with(nil).new
+    assert_equal 'Jamis', jamis.name
+  end
 end
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index b3d4305f7c..109cb2c6bc 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -27,6 +27,12 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal van.id, Minivan.where(:minivan_id => van).to_a.first.minivan_id
   end
 
+  def test_do_not_double_quote_string_id_with_array
+    van = Minivan.last
+    assert van
+    assert_equal van, Minivan.where(:minivan_id => [van]).to_a.first
+  end
+
   def test_bind_values
     relation = Post.scoped
     assert_equal [], relation.bind_values
@@ -539,17 +545,17 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_relation_merging
-    devs = Developer.where("salary >= 80000") & Developer.limit(2) & Developer.order('id ASC').where("id < 3")
+    devs = Developer.where("salary >= 80000").merge(Developer.limit(2)).merge(Developer.order('id ASC').where("id < 3"))
     assert_equal [developers(:david), developers(:jamis)], devs.to_a
 
-    dev_with_count = Developer.limit(1) & Developer.order('id DESC') & Developer.select('developers.*')
+    dev_with_count = Developer.limit(1).merge(Developer.order('id DESC')).merge(Developer.select('developers.*'))
     assert_equal [developers(:poor_jamis)], dev_with_count.to_a
   end
 
   def test_relation_merging_with_eager_load
     relations = []
-    relations << (Post.order('comments.id DESC') & Post.eager_load(:last_comment) & Post.scoped)
-    relations << (Post.eager_load(:last_comment) & Post.order('comments.id DESC') & Post.scoped)
+    relations << Post.order('comments.id DESC').merge(Post.eager_load(:last_comment)).merge(Post.scoped)
+    relations << Post.eager_load(:last_comment).merge(Post.order('comments.id DESC')).merge(Post.scoped)
 
     relations.each do |posts|
       post = posts.find { |p| p.id == 1 }
@@ -558,20 +564,20 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_relation_merging_with_locks
-    devs = Developer.lock.where("salary >= 80000").order("id DESC") & Developer.limit(2)
+    devs = Developer.lock.where("salary >= 80000").order("id DESC").merge(Developer.limit(2))
     assert_present devs.locked
   end
 
   def test_relation_merging_with_preload
     ActiveRecord::IdentityMap.without do
-    [Post.scoped & Post.preload(:author), Post.preload(:author) & Post.scoped].each do |posts|
-      assert_queries(2) { assert posts.first.author }
-    end
+      [Post.scoped.merge(Post.preload(:author)), Post.preload(:author).merge(Post.scoped)].each do |posts|
+        assert_queries(2) { assert posts.first.author }
+      end
     end
   end
 
   def test_relation_merging_with_joins
-    comments = Comment.joins(:post).where(:body => 'Thank you for the welcome') & Post.where(:body => 'Such a lovely day')
+    comments = Comment.joins(:post).where(:body => 'Thank you for the welcome').merge(Post.where(:body => 'Such a lovely day'))
     assert_equal 1, comments.count
   end
 
@@ -636,6 +642,14 @@ class RelationTest < ActiveRecord::TestCase
   def test_any
     posts = Post.scoped
 
+    # This test was failing when run on its own (as opposed to running the entire suite).
+    # The second line in the assert_queries block was causing visit_Arel_Attributes_Attribute
+    # in Arel::Visitors::ToSql to trigger a SHOW TABLES query. Running that line here causes
+    # the SHOW TABLES result to be cached so we don't have to do it again in the block.
+    #
+    # This is obviously a rubbish fix but it's the best I can come up with for now...
+    posts.where(:id => nil).any?
+
     assert_queries(3) do
       assert posts.any? # Uses COUNT()
       assert ! posts.where(:id => nil).any?
@@ -794,4 +808,12 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal [rails_author], [rails_author] & relation
     assert_equal [rails_author], relation & [rails_author]
   end
+
+  def test_removing_limit_with_options
+    assert_not_equal 1, Post.limit(1).all(:limit => nil).count
+  end
+
+  def test_primary_key
+    assert_equal "id", Post.scoped.primary_key
+  end
 end
diff --git a/activerecord/test/cases/serialization_test.rb b/activerecord/test/cases/serialization_test.rb
index 25dbcc9fc2..677d659f39 100644
--- a/activerecord/test/cases/serialization_test.rb
+++ b/activerecord/test/cases/serialization_test.rb
@@ -23,6 +23,12 @@ class SerializationTest < ActiveRecord::TestCase
     @contact = Contact.new(@contact_attributes)
   end
 
+  def test_serialized_init_with
+    topic = Topic.allocate
+    topic.init_with('attributes' => { 'content' => '--- foo' })
+    assert_equal 'foo', topic.content
+  end
+
   def test_to_xml
     xml = REXML::Document.new(topics(:first).to_xml(:indent => 0))
     bonus_time_in_current_timezone = topics(:first).bonus_time.xmlschema
diff --git a/activerecord/test/cases/session_store/session_test.rb b/activerecord/test/cases/session_store/session_test.rb
index 6f1c170a0c..cee5ddd003 100644
--- a/activerecord/test/cases/session_store/session_test.rb
+++ b/activerecord/test/cases/session_store/session_test.rb
@@ -5,7 +5,7 @@ require 'active_record/session_store'
 module ActiveRecord
   class SessionStore
     class SessionTest < ActiveRecord::TestCase
-      self.use_transactional_fixtures = false
+      self.use_transactional_fixtures = false unless supports_savepoints? && ActiveRecord::Base.connection.supports_ddl_transactions?
 
       def setup
         super
@@ -60,6 +60,7 @@ module ActiveRecord
       end
 
       def test_loaded?
+        Session.create_table!
         s = Session.new
         assert !s.loaded?, 'session is not loaded'
       end
diff --git a/activerecord/test/cases/timestamp_test.rb b/activerecord/test/cases/timestamp_test.rb
index 70c098bc6d..1c21f0f3b6 100644
--- a/activerecord/test/cases/timestamp_test.rb
+++ b/activerecord/test/cases/timestamp_test.rb
@@ -140,4 +140,34 @@ class TimestampTest < ActiveRecord::TestCase
   ensure
     Toy.belongs_to :pet
   end
+
+  def test_timestamp_attributes_for_create
+    toy = Toy.first
+    assert_equal toy.send(:timestamp_attributes_for_create), [:created_at, :created_on]
+  end
+
+  def test_timestamp_attributes_for_update
+    toy = Toy.first
+    assert_equal toy.send(:timestamp_attributes_for_update), [:updated_at, :updated_on]
+  end
+
+  def test_all_timestamp_attributes
+    toy = Toy.first
+    assert_equal toy.send(:all_timestamp_attributes), [:created_at, :created_on, :updated_at, :updated_on]
+  end
+
+  def test_timestamp_attributes_for_create_in_model
+    toy = Toy.first
+    assert_equal toy.send(:timestamp_attributes_for_create_in_model), [:created_at]
+  end
+
+  def test_timestamp_attributes_for_update_in_model
+    toy = Toy.first
+    assert_equal toy.send(:timestamp_attributes_for_update_in_model), [:updated_at]
+  end
+
+  def test_all_timestamp_attributes_in_model
+    toy = Toy.first
+    assert_equal toy.send(:all_timestamp_attributes_in_model), [:created_at, :updated_at]
+  end
 end
diff --git a/activerecord/test/cases/unconnected_test.rb b/activerecord/test/cases/unconnected_test.rb
index 23ad10f3f9..f85fb4e5da 100644
--- a/activerecord/test/cases/unconnected_test.rb
+++ b/activerecord/test/cases/unconnected_test.rb
@@ -4,7 +4,7 @@ class TestRecord < ActiveRecord::Base
 end
 
 class TestUnconnectedAdapter < ActiveRecord::TestCase
-  self.use_transactional_fixtures = false
+  self.use_transactional_fixtures = false unless supports_savepoints?
 
   def setup
     @underlying = ActiveRecord::Base.connection
@@ -14,6 +14,7 @@ class TestUnconnectedAdapter < ActiveRecord::TestCase
   def teardown
     @underlying = nil
     ActiveRecord::Base.establish_connection(@specification)
+    load_schema if in_memory_db?
   end
 
   def test_connection_no_longer_established
diff --git a/activerecord/test/cases/validations/uniqueness_validation_test.rb b/activerecord/test/cases/validations/uniqueness_validation_test.rb
index 679d67553b..b4f3dd034c 100644
--- a/activerecord/test/cases/validations/uniqueness_validation_test.rb
+++ b/activerecord/test/cases/validations/uniqueness_validation_test.rb
@@ -6,19 +6,6 @@ require 'models/warehouse_thing'
 require 'models/guid'
 require 'models/event'
 
-# The following methods in Topic are used in test_conditional_validation_*
-class Topic
-  has_many :unique_replies, :dependent => :destroy, :foreign_key => "parent_id"
-  has_many :silly_unique_replies, :dependent => :destroy, :foreign_key => "parent_id"
-end
-
-class UniqueReply < Reply
-  validates_uniqueness_of :content, :scope => 'parent_id'
-end
-
-class SillyUniqueReply < UniqueReply
-end
-
 class Wizard < ActiveRecord::Base
   self.abstract_class = true
 
diff --git a/activerecord/test/cases/yaml_serialization_test.rb b/activerecord/test/cases/yaml_serialization_test.rb
index 0fc9918744..0b54c309d1 100644
--- a/activerecord/test/cases/yaml_serialization_test.rb
+++ b/activerecord/test/cases/yaml_serialization_test.rb
@@ -17,4 +17,30 @@ class YamlSerializationTest < ActiveRecord::TestCase
     t = YAML.load YAML.dump topic
     assert_equal topic, t
   end
+
+  def test_encode_with_coder
+    topic = Topic.first
+    coder = {}
+    topic.encode_with coder
+    assert_equal({'attributes' => topic.attributes}, coder)
+  end
+
+  begin
+    require 'psych'
+
+    def test_psych_roundtrip
+      topic = Topic.first
+      assert topic
+      t = Psych.load Psych.dump topic
+      assert_equal topic, t
+    end
+
+    def test_psych_roundtrip_new_object
+      topic = Topic.new
+      assert topic
+      t = Psych.load Psych.dump topic
+      assert_equal topic.attributes, t.attributes
+    end
+  rescue LoadError
+  end
 end
diff --git a/activerecord/test/connections/native_sqlite3/connection.rb b/activerecord/test/connections/native_sqlite3/connection.rb
index c517c2375e..c2aff5551f 100644
--- a/activerecord/test/connections/native_sqlite3/connection.rb
+++ b/activerecord/test/connections/native_sqlite3/connection.rb
@@ -3,21 +3,12 @@ require_dependency 'models/course'
 require 'logger'
 ActiveRecord::Base.logger = Logger.new("debug.log")
 
-class SqliteError < StandardError
-end
-
 BASE_DIR = FIXTURES_ROOT
 sqlite_test_db  = "#{BASE_DIR}/fixture_database.sqlite3"
 sqlite_test_db2 = "#{BASE_DIR}/fixture_database_2.sqlite3"
 
 def make_connection(clazz, db_file)
   ActiveRecord::Base.configurations = { clazz.name => { :adapter => 'sqlite3', :database => db_file, :timeout => 5000 } }
-  unless File.exist?(db_file)
-    puts "SQLite3 database not found at #{db_file}. Rebuilding it."
-    sqlite_command = %Q{sqlite3 "#{db_file}" "create table a (a integer); drop table a;"}
-    puts "Executing '#{sqlite_command}'"
-    raise SqliteError.new("Seems that there is no sqlite3 executable available") unless system(sqlite_command)
-  end
   clazz.establish_connection(clazz.name)
 end
 
diff --git a/activerecord/test/connections/native_sqlite3/in_memory_connection.rb b/activerecord/test/connections/native_sqlite3/in_memory_connection.rb
deleted file mode 100644
index 6aba9719bb..0000000000
--- a/activerecord/test/connections/native_sqlite3/in_memory_connection.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-print "Using native SQLite3\n"
-require_dependency 'models/course'
-require 'logger'
-ActiveRecord::Base.logger = Logger.new("debug.log")
-
-class SqliteError < StandardError
-end
-
-def make_connection(clazz, db_definitions_file)
-  clazz.establish_connection(:adapter => 'sqlite3', :database  => ':memory:')
-  File.read(SCHEMA_ROOT + "/#{db_definitions_file}").split(';').each do |command|
-    clazz.connection.execute(command) unless command.strip.empty?
-  end
-end
-
-make_connection(ActiveRecord::Base, 'sqlite.sql')
-make_connection(Course, 'sqlite2.sql')
-load(SCHEMA_ROOT + "/schema.rb")
diff --git a/activerecord/test/connections/native_sqlite3_mem/connection.rb b/activerecord/test/connections/native_sqlite3_mem/connection.rb
new file mode 100644
index 0000000000..14e10900d1
--- /dev/null
+++ b/activerecord/test/connections/native_sqlite3_mem/connection.rb
@@ -0,0 +1,19 @@
+# This file connects to an in-memory SQLite3 database, which is a very fast way to run the tests.
+# The downside is that disconnect from the database results in the database effectively being
+# wiped. For this reason, pooled_connections_test.rb is disabled when using an in-memory database.
+
+print "Using native SQLite3 (in memory)\n"
+require_dependency 'models/course'
+require 'logger'
+ActiveRecord::Base.logger = Logger.new("debug.log")
+
+class SqliteError < StandardError
+end
+
+def make_connection(clazz)
+  ActiveRecord::Base.configurations = { clazz.name => { :adapter => 'sqlite3', :database  => ':memory:' } }
+  clazz.establish_connection(clazz.name)
+end
+
+make_connection(ActiveRecord::Base)
+make_connection(Course)
diff --git a/activerecord/test/fixtures/companies.yml b/activerecord/test/fixtures/companies.yml
index ffaa097686..a982d3921d 100644
--- a/activerecord/test/fixtures/companies.yml
+++ b/activerecord/test/fixtures/companies.yml
@@ -12,6 +12,7 @@ first_firm:
   type: Firm
   name: 37signals
   ruby_type: Firm
+  firm_id: 1
 
 second_client:
   id: 3
diff --git a/activerecord/test/fixtures/dashboards.yml b/activerecord/test/fixtures/dashboards.yml
index e75bf46e6c..a4c7e0d309 100644
--- a/activerecord/test/fixtures/dashboards.yml
+++ b/activerecord/test/fixtures/dashboards.yml
@@ -1,3 +1,6 @@
 cool_first:
   dashboard_id: d1
-  name: my_dashboard
\ No newline at end of file
+  name: my_dashboard
+second:
+  dashboard_id: d2
+  name: second
diff --git a/activerecord/test/fixtures/members.yml b/activerecord/test/fixtures/members.yml
index 6db945e61d..824840b7e5 100644
--- a/activerecord/test/fixtures/members.yml
+++ b/activerecord/test/fixtures/members.yml
@@ -1,6 +1,8 @@
 groucho:
+  id: 1
   name: Groucho Marx
   member_type_id: 1
 some_other_guy:
+  id: 2
   name: Englebert Humperdink
   member_type_id: 2
diff --git a/activerecord/test/fixtures/memberships.yml b/activerecord/test/fixtures/memberships.yml
index b9722dbc8a..eed8b22af8 100644
--- a/activerecord/test/fixtures/memberships.yml
+++ b/activerecord/test/fixtures/memberships.yml
@@ -1,20 +1,20 @@
 membership_of_boring_club:
   joined_on: <%= 3.weeks.ago.to_s(:db) %>
   club: boring_club
-  member: groucho
+  member_id: 1
   favourite: false
   type: CurrentMembership
 
 membership_of_favourite_club:
   joined_on: <%= 3.weeks.ago.to_s(:db) %>
   club: moustache_club
-  member: groucho
+  member_id: 1
   favourite: true
   type: Membership
 
 other_guys_membership:
   joined_on: <%= 4.weeks.ago.to_s(:db) %>
   club: boring_club
-  member: some_other_guy
+  member_id: 2
   favourite: false
   type: CurrentMembership
diff --git a/activerecord/test/fixtures/posts.yml b/activerecord/test/fixtures/posts.yml
index f817493190..07069a064f 100644
--- a/activerecord/test/fixtures/posts.yml
+++ b/activerecord/test/fixtures/posts.yml
@@ -5,6 +5,7 @@ welcome:
   body: Such a lovely day
   comments_count: 2
   taggings_count: 1
+  tags_count: 1
   type: Post
 
 thinking:
@@ -14,6 +15,7 @@ thinking:
   body: Like I hopefully always am
   comments_count: 1
   taggings_count: 1
+  tags_count: 1
   type: SpecialPost
 
 authorless:
diff --git a/activerecord/test/fixtures/ships.yml b/activerecord/test/fixtures/ships.yml
index 137055aad1..df914262b3 100644
--- a/activerecord/test/fixtures/ships.yml
+++ b/activerecord/test/fixtures/ships.yml
@@ -1,5 +1,6 @@
 black_pearl:
   name: "Black Pearl"
+  pirate: blackbeard
 interceptor:
   id: 2
   name: "Interceptor"
diff --git a/activerecord/test/fixtures/speedometers.yml b/activerecord/test/fixtures/speedometers.yml
index 6a471aba0a..e12398f0c4 100644
--- a/activerecord/test/fixtures/speedometers.yml
+++ b/activerecord/test/fixtures/speedometers.yml
@@ -1,4 +1,8 @@
 cool_first:
   speedometer_id: s1
   name: my_speedometer
-  dashboard_id: d1
\ No newline at end of file
+  dashboard_id: d1
+second:
+  speedometer_id: s2
+  name: second
+  dashboard_id: d2
diff --git a/activerecord/test/fixtures/sponsors.yml b/activerecord/test/fixtures/sponsors.yml
index 42df8957d1..bfc6b238b1 100644
--- a/activerecord/test/fixtures/sponsors.yml
+++ b/activerecord/test/fixtures/sponsors.yml
@@ -1,9 +1,12 @@
 moustache_club_sponsor_for_groucho:
   sponsor_club: moustache_club
-  sponsorable: groucho (Member)
+  sponsorable_id: 1
+  sponsorable_type: Member
 boring_club_sponsor_for_groucho:
   sponsor_club: boring_club
-  sponsorable: some_other_guy (Member)
+  sponsorable_id: 2
+  sponsorable_type: Member
 crazy_club_sponsor_for_groucho:
   sponsor_club: crazy_club
-  sponsorable: some_other_guy (Member)
\ No newline at end of file
+  sponsorable_id: 2
+  sponsorable_type: Member
diff --git a/activerecord/test/fixtures/traffic_lights.yml b/activerecord/test/fixtures/traffic_lights.yml
new file mode 100644
index 0000000000..6dabd53474
--- /dev/null
+++ b/activerecord/test/fixtures/traffic_lights.yml
@@ -0,0 +1,6 @@
+uk:
+  location: UK
+  state:
+    - Green
+    - Red
+    - Orange
diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb
index fd6d2b384a..83a6f5d926 100644
--- a/activerecord/test/models/author.rb
+++ b/activerecord/test/models/author.rb
@@ -28,7 +28,9 @@ class Author < ActiveRecord::Base
 
   has_many :first_posts
   has_many :comments_on_first_posts, :through => :first_posts, :source => :comments, :order => 'posts.id desc, comments.id asc'
-  has_one  :comment_on_first_posts,  :through => :first_posts, :source => :comments, :order => 'posts.id desc, comments.id asc'
+
+  has_one :first_post
+  has_one :comment_on_first_post,  :through => :first_post, :source => :comments, :order => 'posts.id desc, comments.id asc'
 
   has_many :thinking_posts, :class_name => 'Post', :conditions => { :title => 'So I was thinking' }, :dependent => :delete_all
   has_many :welcome_posts,  :class_name => 'Post', :conditions => { :title => 'Welcome to the weblog' }
@@ -76,6 +78,7 @@ class Author < ActiveRecord::Base
 
   has_many :categorizations
   has_many :categories, :through => :categorizations
+  has_many :named_categories, :through => :categorizations
 
   has_many :special_categorizations
   has_many :special_categories, :through => :special_categorizations, :source => :category
diff --git a/activerecord/test/models/bulb.rb b/activerecord/test/models/bulb.rb
index 9eefc5803a..7178bb0d00 100644
--- a/activerecord/test/models/bulb.rb
+++ b/activerecord/test/models/bulb.rb
@@ -1,7 +1,14 @@
 class Bulb < ActiveRecord::Base
-  
+
   default_scope :conditions => {:name => 'defaulty' }
-  
+
   belongs_to :car
 
+  attr_reader :scoped_methods_after_initialize
+
+  after_initialize :record_scoped_methods_after_initialize
+  def record_scoped_methods_after_initialize
+    @scoped_methods_after_initialize = self.class.scoped_methods.dup
+  end
+
 end
diff --git a/activerecord/test/models/categorization.rb b/activerecord/test/models/categorization.rb
index fdb0a11540..45f50e4af3 100644
--- a/activerecord/test/models/categorization.rb
+++ b/activerecord/test/models/categorization.rb
@@ -1,6 +1,7 @@
 class Categorization < ActiveRecord::Base
   belongs_to :post
   belongs_to :category
+  belongs_to :named_category, :class_name => 'Category', :foreign_key => :named_category_name, :primary_key => :name
   belongs_to :author
 
   belongs_to :author_using_custom_pk,  :class_name => 'Author', :foreign_key => :author_id, :primary_key => :author_address_extra_id
diff --git a/activerecord/test/models/category.rb b/activerecord/test/models/category.rb
index 48415846dd..06908ea85e 100644
--- a/activerecord/test/models/category.rb
+++ b/activerecord/test/models/category.rb
@@ -23,6 +23,8 @@ class Category < ActiveRecord::Base
 
   has_many :categorizations
   has_many :authors, :through => :categorizations, :select => 'authors.*, categorizations.post_id'
+
+  scope :general, :conditions => { :name => 'General' }
 end
 
 class SpecialCategory < Category
diff --git a/activerecord/test/models/club.rb b/activerecord/test/models/club.rb
index 6e7cdd643a..c432a6ace8 100644
--- a/activerecord/test/models/club.rb
+++ b/activerecord/test/models/club.rb
@@ -1,4 +1,5 @@
 class Club < ActiveRecord::Base
+  has_one :membership
   has_many :memberships
   has_many :members, :through => :memberships
   has_many :current_memberships
@@ -10,4 +11,4 @@ class Club < ActiveRecord::Base
   def private_method
     "I'm sorry sir, this is a *private* club, not a *pirate* club"
   end
-end
\ No newline at end of file
+end
diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index 88061b2145..ff533717cc 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -1,6 +1,7 @@
 class Comment < ActiveRecord::Base
   scope :limit_by, lambda {|l| limit(l) }
   scope :containing_the_letter_e, :conditions => "comments.body LIKE '%e%'"
+  scope :not_again, where("comments.body NOT LIKE '%again%'")
   scope :for_first_post, :conditions => { :post_id => 1 }
   scope :for_first_author,
               :joins => :post,
@@ -15,6 +16,11 @@ class Comment < ActiveRecord::Base
   def self.search_by_type(q)
     self.find(:all, :conditions => ["#{QUOTED_TYPE} = ?", q])
   end
+
+  def self.all_as_method
+    all
+  end
+  scope :all_as_scope, {}
 end
 
 class SpecialComment < Comment
diff --git a/activerecord/test/models/company.rb b/activerecord/test/models/company.rb
index ee5f77b613..e0b30efd51 100644
--- a/activerecord/test/models/company.rb
+++ b/activerecord/test/models/company.rb
@@ -38,7 +38,9 @@ end
 class Firm < Company
   has_many :clients, :order => "id", :dependent => :destroy, :counter_sql =>
       "SELECT COUNT(*) FROM companies WHERE firm_id = 1 " +
-      "AND (#{QUOTED_TYPE} = 'Client' OR #{QUOTED_TYPE} = 'SpecialClient' OR #{QUOTED_TYPE} = 'VerySpecialClient' )"
+      "AND (#{QUOTED_TYPE} = 'Client' OR #{QUOTED_TYPE} = 'SpecialClient' OR #{QUOTED_TYPE} = 'VerySpecialClient' )",
+      :before_remove => :log_before_remove,
+      :after_remove  => :log_after_remove
   has_many :unsorted_clients, :class_name => "Client"
   has_many :clients_sorted_desc, :class_name => "Client", :order => "id DESC"
   has_many :clients_of_firm, :foreign_key => "client_of", :class_name => "Client", :order => "id"
@@ -46,20 +48,16 @@ class Firm < Company
   has_many :dependent_clients_of_firm, :foreign_key => "client_of", :class_name => "Client", :order => "id", :dependent => :destroy
   has_many :exclusively_dependent_clients_of_firm, :foreign_key => "client_of", :class_name => "Client", :order => "id", :dependent => :delete_all
   has_many :limited_clients, :class_name => "Client", :limit => 1
+  has_many :clients_with_interpolated_conditions, :class_name => "Client", :conditions => proc { "rating > #{rating}" }
   has_many :clients_like_ms, :conditions => "name = 'Microsoft'", :class_name => "Client", :order => "id"
-  has_many :clients_with_interpolated_conditions, :class_name => "Client", :conditions => 'rating > #{rating}'
   has_many :clients_like_ms_with_hash_conditions, :conditions => { :name => 'Microsoft' }, :class_name => "Client", :order => "id"
-  has_many :clients_using_sql, :class_name => "Client", :finder_sql => 'SELECT * FROM companies WHERE client_of = #{id}'
-  has_many :clients_using_multiline_sql, :class_name => "Client", :finder_sql => '
-  SELECT
-  companies.*
-  FROM companies WHERE companies.client_of = #{id}'
+  has_many :clients_using_sql, :class_name => "Client", :finder_sql => proc { "SELECT * FROM companies WHERE client_of = #{id}" }
   has_many :clients_using_counter_sql, :class_name => "Client",
-           :finder_sql  => 'SELECT * FROM companies WHERE client_of = #{id}',
-           :counter_sql => 'SELECT COUNT(*) FROM companies WHERE client_of = #{id}'
+           :finder_sql  => proc { "SELECT * FROM companies WHERE client_of = #{id} " },
+           :counter_sql => proc { "SELECT COUNT(*) FROM companies WHERE client_of = #{id}" }
   has_many :clients_using_zero_counter_sql, :class_name => "Client",
-           :finder_sql  => 'SELECT * FROM companies WHERE client_of = #{id}',
-           :counter_sql => 'SELECT 0 FROM companies WHERE client_of = #{id}'
+           :finder_sql  => proc { "SELECT * FROM companies WHERE client_of = #{id}" },
+           :counter_sql => proc { "SELECT 0 FROM companies WHERE client_of = #{id}" }
   has_many :no_clients_using_counter_sql, :class_name => "Client",
            :finder_sql  => 'SELECT * FROM companies WHERE client_of = 1000',
            :counter_sql => 'SELECT COUNT(*) FROM companies WHERE client_of = 1000'
@@ -88,6 +86,19 @@ class Firm < Company
   has_one :unautosaved_account, :foreign_key => "firm_id", :class_name => 'Account', :autosave => false
   has_many :accounts
   has_many :unautosaved_accounts, :foreign_key => "firm_id", :class_name => 'Account', :autosave => false
+
+  def log
+    @log ||= []
+  end
+
+  private
+    def log_before_remove(record)
+      log << "before_remove#{record.id}"
+    end
+
+    def log_after_remove(record)
+      log << "after_remove#{record.id}"
+    end
 end
 
 class DependentFirm < Company
@@ -109,6 +120,9 @@ class Client < Company
   belongs_to :firm_with_primary_key, :class_name => "Firm", :primary_key => "name", :foreign_key => "firm_name"
   belongs_to :firm_with_primary_key_symbols, :class_name => "Firm", :primary_key => :name, :foreign_key => :firm_name
   belongs_to :readonly_firm, :class_name => "Firm", :foreign_key => "firm_id", :readonly => true
+  belongs_to :bob_firm, :class_name => "Firm", :foreign_key => "client_of", :conditions => { :name => "Bob" }
+  has_many :accounts, :through => :firm
+  belongs_to :account
 
   # Record destruction so we can test whether firm.clients.clear has
   # is calling client.destroy, deleting from the database, or setting
diff --git a/activerecord/test/models/contact.rb b/activerecord/test/models/contact.rb
index 975a885331..e081eee661 100644
--- a/activerecord/test/models/contact.rb
+++ b/activerecord/test/models/contact.rb
@@ -1,8 +1,14 @@
 class Contact < ActiveRecord::Base
+  establish_connection(:adapter => 'fake')
+
+  connection.tables = ['contacts']
+  connection.primary_keys = {
+    'contacts' => 'id'
+  }
+
   # mock out self.columns so no pesky db is needed for these tests
   def self.column(name, sql_type = nil, options = {})
-    @columns ||= []
-    @columns << ActiveRecord::ConnectionAdapters::Column.new(name.to_s, options[:default], sql_type.to_s, options[:null])
+    connection.merge_column('contacts', name, sql_type, options)
   end
 
   column :name,        :string
diff --git a/activerecord/test/models/customer.rb b/activerecord/test/models/customer.rb
index e258ccdb6c..777f6b5ba0 100644
--- a/activerecord/test/models/customer.rb
+++ b/activerecord/test/models/customer.rb
@@ -70,4 +70,4 @@ class Fullname
   def to_s
     "#{first} #{last.upcase}"
   end
-end
\ No newline at end of file
+end
diff --git a/activerecord/test/models/joke.rb b/activerecord/test/models/joke.rb
index 3978abc2ba..d7f01e59e6 100644
--- a/activerecord/test/models/joke.rb
+++ b/activerecord/test/models/joke.rb
@@ -1,3 +1,7 @@
 class Joke < ActiveRecord::Base
   set_table_name 'funny_jokes'
 end
+
+class GoodJoke < ActiveRecord::Base
+  set_table_name 'funny_jokes'
+end
diff --git a/activerecord/test/models/lesson.rb b/activerecord/test/models/lesson.rb
new file mode 100644
index 0000000000..4c88153068
--- /dev/null
+++ b/activerecord/test/models/lesson.rb
@@ -0,0 +1,11 @@
+class LessonError < Exception
+end
+
+class Lesson < ActiveRecord::Base
+  has_and_belongs_to_many :students
+  before_destroy :ensure_no_students
+
+  def ensure_no_students
+    raise LessonError unless students.empty?
+  end
+end
diff --git a/activerecord/test/models/member.rb b/activerecord/test/models/member.rb
index 255fb569d7..e6e78f9e45 100644
--- a/activerecord/test/models/member.rb
+++ b/activerecord/test/models/member.rb
@@ -1,12 +1,19 @@
 class Member < ActiveRecord::Base
   has_one :current_membership
-  has_many :memberships
+  has_one :membership
   has_many :fellow_members, :through => :club, :source => :members
   has_one :club, :through => :current_membership
-  has_one :favourite_club, :through => :memberships, :conditions => ["memberships.favourite = ?", true], :source => :club
+  has_one :favourite_club, :through => :membership, :conditions => ["memberships.favourite = ?", true], :source => :club
+  has_one :hairy_club, :through => :membership, :conditions => {:clubs => {:name => "Moustache and Eyebrow Fancier Club"}}, :source => :club
   has_one :sponsor, :as => :sponsorable
   has_one :sponsor_club, :through => :sponsor
   has_one :member_detail
   has_one :organization, :through => :member_detail
   belongs_to :member_type
-end
\ No newline at end of file
+
+  has_many :current_memberships
+  has_one :club_through_many, :through => :current_memberships, :source => :club
+
+  has_many :current_memberships, :conditions => { :favourite => true }
+  has_many :clubs, :through => :current_memberships
+end
diff --git a/activerecord/test/models/person.rb b/activerecord/test/models/person.rb
index bee89de042..a18b9e44df 100644
--- a/activerecord/test/models/person.rb
+++ b/activerecord/test/models/person.rb
@@ -6,10 +6,14 @@ class Person < ActiveRecord::Base
   has_many :references
   has_many :bad_references
   has_many :fixed_bad_references, :conditions => { :favourite => true }, :class_name => 'BadReference'
-  has_many :jobs, :through => :references
   has_one :favourite_reference, :class_name => 'Reference', :conditions => ['favourite=?', true]
   has_many :posts_with_comments_sorted_by_comment_id, :through => :readers, :source => :post, :include => :comments, :order => 'comments.id'
 
+  has_many :jobs, :through => :references
+  has_many :jobs_with_dependent_destroy, :source => :job, :through => :references, :dependent => :destroy
+  has_many :jobs_with_dependent_delete_all, :source => :job, :through => :references, :dependent => :delete_all
+  has_many :jobs_with_dependent_nullify, :source => :job, :through => :references, :dependent => :nullify
+
   belongs_to :primary_contact, :class_name => 'Person'
   has_many :agents, :class_name => 'Person', :foreign_key => 'primary_contact_id'
   has_many :agents_of_agents, :through => :agents, :source => :agents
@@ -18,3 +22,24 @@ class Person < ActiveRecord::Base
   scope :males, :conditions => { :gender => 'M' }
   scope :females, :conditions => { :gender => 'F' }
 end
+
+class PersonWithDependentDestroyJobs < ActiveRecord::Base
+  self.table_name = 'people'
+
+  has_many :references, :foreign_key => :person_id
+  has_many :jobs, :source => :job, :through => :references, :dependent => :destroy
+end
+
+class PersonWithDependentDeleteAllJobs < ActiveRecord::Base
+  self.table_name = 'people'
+
+  has_many :references, :foreign_key => :person_id
+  has_many :jobs, :source => :job, :through => :references, :dependent => :delete_all
+end
+
+class PersonWithDependentNullifyJobs < ActiveRecord::Base
+  self.table_name = 'people'
+
+  has_many :references, :foreign_key => :person_id
+  has_many :jobs, :source => :job, :through => :references, :dependent => :nullify
+end
diff --git a/activerecord/test/models/pirate.rb b/activerecord/test/models/pirate.rb
index f2c45053e7..0d3f62bb33 100644
--- a/activerecord/test/models/pirate.rb
+++ b/activerecord/test/models/pirate.rb
@@ -34,6 +34,8 @@ class Pirate < ActiveRecord::Base
     :after_remove   => proc {|p,b| p.ship_log << "after_removing_proc_bird_#{b.id}"}
   has_many :birds_with_reject_all_blank, :class_name => "Bird"
 
+  has_one :bulb, :foreign_key => :car_id
+
   accepts_nested_attributes_for :parrots, :birds, :allow_destroy => true, :reject_if => proc { |attributes| attributes.empty? }
   accepts_nested_attributes_for :ship, :allow_destroy => true, :reject_if => proc { |attributes| attributes.empty? }
   accepts_nested_attributes_for :update_only_ship, :update_only => true
@@ -78,3 +80,7 @@ class Pirate < ActiveRecord::Base
       ship_log << "#{callback}_#{record.class.name.downcase}_#{record.id || '<new>'}"
     end
 end
+
+class DestructivePirate < Pirate
+  has_one :dependent_ship, :class_name => 'Ship', :foreign_key => :pirate_id, :dependent => :destroy
+end
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index 974e87d2bf..5f29196790 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -38,9 +38,11 @@ class Post < ActiveRecord::Base
   end
 
   has_many :author_favorites, :through => :author
+  has_many :author_categorizations, :through => :author, :source => :categorizations
+  has_many :author_addresses, :through => :author
 
   has_many :comments_with_interpolated_conditions, :class_name => 'Comment',
-      :conditions => ['#{"#{aliased_table_name}." rescue ""}body = ?', 'Thank you for the welcome']
+    :conditions => proc { ["#{"#{aliased_table_name}." rescue ""}body = ?", 'Thank you for the welcome'] }
 
   has_one  :very_special_comment
   has_one  :very_special_comment_with_post, :class_name => "VerySpecialComment", :include => :post
@@ -53,11 +55,21 @@ class Post < ActiveRecord::Base
   has_many :taggings, :as => :taggable
   has_many :tags, :through => :taggings do
     def add_joins_and_select
-      find :all, :select => 'tags.*, authors.id as author_id', :include => false,
+      find :all, :select => 'tags.*, authors.id as author_id',
         :joins => 'left outer join posts on taggings.taggable_id = posts.id left outer join authors on posts.author_id = authors.id'
     end
   end
 
+  has_many :interpolated_taggings, :class_name => 'Tagging', :as => :taggable, :conditions => proc { "1 = #{1}" }
+  has_many :interpolated_tags, :through => :taggings
+  has_many :interpolated_tags_2, :through => :interpolated_taggings, :source => :tag
+
+  has_many :taggings_with_delete_all, :class_name => 'Tagging', :as => :taggable, :dependent => :delete_all
+  has_many :taggings_with_destroy, :class_name => 'Tagging', :as => :taggable, :dependent => :destroy
+
+  has_many :tags_with_destroy, :through => :taggings, :source => :tag, :dependent => :destroy
+  has_many :tags_with_nullify, :through => :taggings, :source => :tag, :dependent => :nullify
+
   has_many :misc_tags, :through => :taggings, :source => :tag, :conditions => "tags.name = 'Misc'"
   has_many :funky_tags, :through => :taggings, :source => :tag
   has_many :super_tags, :through => :taggings
diff --git a/activerecord/test/models/project.rb b/activerecord/test/models/project.rb
index 416032cb75..efe1ce67da 100644
--- a/activerecord/test/models/project.rb
+++ b/activerecord/test/models/project.rb
@@ -7,14 +7,15 @@ class Project < ActiveRecord::Base
   has_and_belongs_to_many :developers_named_david, :class_name => "Developer", :conditions => "name = 'David'", :uniq => true
   has_and_belongs_to_many :developers_named_david_with_hash_conditions, :class_name => "Developer", :conditions => { :name => 'David' }, :uniq => true
   has_and_belongs_to_many :salaried_developers, :class_name => "Developer", :conditions => "salary > 0"
-  has_and_belongs_to_many :developers_with_finder_sql, :class_name => "Developer", :finder_sql => 'SELECT t.*, j.* FROM developers_projects j, developers t WHERE t.id = j.developer_id AND j.project_id = #{id} ORDER BY t.id'
-  has_and_belongs_to_many :developers_with_multiline_finder_sql, :class_name => "Developer", :finder_sql => '
-    SELECT
-      t.*, j.*
-    FROM
-      developers_projects j,
-      developers t WHERE t.id = j.developer_id AND j.project_id = #{id} ORDER BY t.id'
-  has_and_belongs_to_many :developers_by_sql, :class_name => "Developer", :delete_sql => "DELETE FROM developers_projects WHERE project_id = \#{id} AND developer_id = \#{record.id}"
+  has_and_belongs_to_many :developers_with_finder_sql, :class_name => "Developer", :finder_sql => proc { "SELECT t.*, j.* FROM developers_projects j, developers t WHERE t.id = j.developer_id AND j.project_id = #{id} ORDER BY t.id" }
+  has_and_belongs_to_many :developers_with_multiline_finder_sql, :class_name => "Developer", :finder_sql => proc {
+    "SELECT
+       t.*, j.*
+     FROM
+       developers_projects j,
+       developers t WHERE t.id = j.developer_id AND j.project_id = #{id} ORDER BY t.id"
+  }
+  has_and_belongs_to_many :developers_by_sql, :class_name => "Developer", :delete_sql => proc { |record| "DELETE FROM developers_projects WHERE project_id = #{id} AND developer_id = #{record.id}" }
   has_and_belongs_to_many :developers_with_callbacks, :class_name => "Developer", :before_add => Proc.new {|o, r| o.developers_log << "before_adding#{r.id || '<new>'}"},
                             :after_add => Proc.new {|o, r| o.developers_log << "after_adding#{r.id || '<new>'}"},
                             :before_remove => Proc.new {|o, r| o.developers_log << "before_removing#{r.id}"},
@@ -28,6 +29,10 @@ class Project < ActiveRecord::Base
     @developers_log = []
   end
 
+  def self.all_as_method
+    all
+  end
+  scope :all_as_scope, {}
 end
 
 class SpecialProject < Project
diff --git a/activerecord/test/models/reference.rb b/activerecord/test/models/reference.rb
index 4a17c936f5..06c4f79ef3 100644
--- a/activerecord/test/models/reference.rb
+++ b/activerecord/test/models/reference.rb
@@ -1,6 +1,18 @@
 class Reference < ActiveRecord::Base
   belongs_to :person
   belongs_to :job
+
+  class << self
+    attr_accessor :make_comments
+  end
+
+  before_destroy :make_comments
+
+  def make_comments
+    if self.class.make_comments
+      person.update_attributes :comments => "Reference destroyed"
+    end
+  end
 end
 
 class BadReference < ActiveRecord::Base
diff --git a/activerecord/test/models/reply.rb b/activerecord/test/models/reply.rb
index 110d540120..6adfe0ae3c 100644
--- a/activerecord/test/models/reply.rb
+++ b/activerecord/test/models/reply.rb
@@ -10,6 +10,13 @@ class Reply < Topic
   attr_accessible :title, :author_name, :author_email_address, :written_on, :content, :last_read, :parent_title
 end
 
+class UniqueReply < Reply
+  validates_uniqueness_of :content, :scope => 'parent_id'
+end
+
+class SillyUniqueReply < UniqueReply
+end
+
 class WrongReply < Reply
   validate :errors_on_empty_content
   validate :title_is_wrong_create, :on => :create
diff --git a/activerecord/test/models/sponsor.rb b/activerecord/test/models/sponsor.rb
index 50c2c2d76c..aa4a3638fd 100644
--- a/activerecord/test/models/sponsor.rb
+++ b/activerecord/test/models/sponsor.rb
@@ -1,4 +1,7 @@
 class Sponsor < ActiveRecord::Base
   belongs_to :sponsor_club, :class_name => "Club", :foreign_key => "club_id"
   belongs_to :sponsorable, :polymorphic => true
-end
\ No newline at end of file
+  belongs_to :thing, :polymorphic => true, :foreign_type => :sponsorable_type, :foreign_key => :sponsorable_id
+  belongs_to :sponsorable_with_conditions, :polymorphic => true,
+             :foreign_type => 'sponsorable_type', :foreign_key => 'sponsorable_id', :conditions => {:name => 'Ernie'}
+end
diff --git a/activerecord/test/models/student.rb b/activerecord/test/models/student.rb
new file mode 100644
index 0000000000..f459f2a9a3
--- /dev/null
+++ b/activerecord/test/models/student.rb
@@ -0,0 +1,3 @@
+class Student < ActiveRecord::Base
+  has_and_belongs_to_many :lessons
+end
diff --git a/activerecord/test/models/tagging.rb b/activerecord/test/models/tagging.rb
index a1fa1a9750..231d2b5890 100644
--- a/activerecord/test/models/tagging.rb
+++ b/activerecord/test/models/tagging.rb
@@ -6,5 +6,7 @@ class Tagging < ActiveRecord::Base
   belongs_to :tag, :include => :tagging
   belongs_to :super_tag,   :class_name => 'Tag', :foreign_key => 'super_tag_id'
   belongs_to :invalid_tag, :class_name => 'Tag', :foreign_key => 'tag_id'
+  belongs_to :interpolated_tag, :class_name => 'Tag', :foreign_key => :tag_id, :conditions => proc { "1 = #{1}" }
   belongs_to :taggable, :polymorphic => true, :counter_cache => true
-end
\ No newline at end of file
+  has_many :things, :through => :taggable
+end
diff --git a/activerecord/test/models/task.rb b/activerecord/test/models/task.rb
index ee0282c79b..e36989dd56 100644
--- a/activerecord/test/models/task.rb
+++ b/activerecord/test/models/task.rb
@@ -1,3 +1,5 @@
 class Task < ActiveRecord::Base
-
+  def updated_at
+    ending
+  end
 end
diff --git a/activerecord/test/models/topic.rb b/activerecord/test/models/topic.rb
index 6496f36f7e..6440dbe8ab 100644
--- a/activerecord/test/models/topic.rb
+++ b/activerecord/test/models/topic.rb
@@ -45,6 +45,10 @@ class Topic < ActiveRecord::Base
 
   has_many :replies, :dependent => :destroy, :foreign_key => "parent_id"
   has_many :replies_with_primary_key, :class_name => "Reply", :dependent => :destroy, :primary_key => "title", :foreign_key => "parent_title"
+
+  has_many :unique_replies, :dependent => :destroy, :foreign_key => "parent_id"
+  has_many :silly_unique_replies, :dependent => :destroy, :foreign_key => "parent_id"
+
   serialize :content
 
   before_create  :default_written_on
diff --git a/activerecord/test/models/traffic_light.rb b/activerecord/test/models/traffic_light.rb
new file mode 100644
index 0000000000..228f3f7bd4
--- /dev/null
+++ b/activerecord/test/models/traffic_light.rb
@@ -0,0 +1,3 @@
+class TrafficLight < ActiveRecord::Base
+  serialize :state, Array
+end
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 177045ac51..0b3865fc78 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -110,6 +110,7 @@ ActiveRecord::Schema.define do
 
   create_table :categorizations, :force => true do |t|
     t.column :category_id, :integer
+    t.string :named_category_name
     t.column :post_id, :integer
     t.column :author_id, :integer
     t.column :special, :boolean
@@ -142,6 +143,7 @@ ActiveRecord::Schema.define do
       t.text    :body, :null => false
     end
     t.string  :type
+    t.integer :taggings_count, :default => 0
   end
 
   create_table :companies, :force => true do |t|
@@ -152,6 +154,7 @@ ActiveRecord::Schema.define do
     t.string  :name
     t.integer :client_of
     t.integer :rating, :default => 1
+    t.integer :account_id
   end
 
   add_index :companies, [:firm_id, :type, :rating, :ruby_type], :name => "company_index"
@@ -226,6 +229,10 @@ ActiveRecord::Schema.define do
     t.string :name
   end
 
+  create_table :cold_jokes, :force => true do |t|
+    t.string :name
+  end
+
   create_table :goofy_string_id, :force => true, :id => false do |t|
     t.string :id, :null => false
     t.string :info
@@ -276,6 +283,15 @@ ActiveRecord::Schema.define do
     t.integer :version, :null => false, :default => 0
   end
 
+  create_table :lessons, :force => true do |t|
+    t.string :name
+  end
+
+  create_table :lessons_students, :id => false, :force => true do |t|
+    t.references :lesson
+    t.references :student
+  end
+
   create_table :line_items, :force => true do |t|
     t.integer :invoice_id
     t.integer :amount
@@ -413,6 +429,8 @@ ActiveRecord::Schema.define do
     t.string     :gender, :limit => 1
     t.references :number1_fan
     t.integer    :lock_version, :null => false, :default => 0
+    t.string     :comments
+    t.timestamps
   end
 
   create_table :pets, :primary_key => :pet_id ,:force => true do |t|
@@ -441,6 +459,11 @@ ActiveRecord::Schema.define do
     t.string  :type
     t.integer :comments_count, :default => 0
     t.integer :taggings_count, :default => 0
+    t.integer :taggings_with_delete_all_count, :default => 0
+    t.integer :taggings_with_destroy_count, :default => 0
+    t.integer :tags_count, :default => 0
+    t.integer :tags_with_destroy_count, :default => 0
+    t.integer :tags_with_nullify_count, :default => 0
   end
 
   create_table :price_estimates, :force => true do |t|
@@ -505,6 +528,10 @@ ActiveRecord::Schema.define do
     t.string :sponsorable_type
   end
 
+  create_table :students, :force => true do |t|
+    t.string :name
+  end
+
   create_table :subscribers, :force => true, :id => false do |t|
     t.string :nick, :null => false
     t.string :name