Merge branch 'master' of github.com:lifo/docrails

* 'master' of github.com:lifo/docrails: (57 commits)
  Made the defaults section a little more readable and more to the point, giving a overview of the possibilities.
  Added information about default values
  added .'s to headings in the initialization textile page
  s/ERb/ERB/g (part II)
  s/ERb/ERB/g
  Bump up erubis to 2.7.0
  Implicit actions named not_implemented can be rendered
  Gem::Specification#has_rdoc= is deprecated since rubygems 1.7.0
  default_executable is deprecated since rubygems 1.7.0
  Trivial fix to HTTP Digest auth MD5 example
  Moved Turn activation/dependency to railties
  fix typo
  Direct logging of Active Record to STDOUT so it's shown inline with the results in the console [DHH]
  Add using Turn with natural language test case names if the library is available (which it will be in Rails 3.1) [DHH]
  require turn only for minitest
  Use Turn to format all Rails tests and enable the natural language case names
  Improve docs.
  pass respond_with options to controller render when using a template for api navigation
  only try to display an api template in responders if the request is a get or there are no errors
  when using respond_with with an invalid resource and custom options, the default response status and error messages should be returned
  ...

1 files changed, 10 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 563843f3cc..8fa315bdf3 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -183,7 +183,9 @@ module ActiveRecord
     def exists?(id = nil)
       id = id.id if ActiveRecord::Base === id
 
-      relation = select("1").limit(1)
+      join_dependency = construct_join_dependency_for_association_find
+      relation = construct_relation_for_association_find(join_dependency)
+      relation = relation.except(:select).select("1").limit(1)
 
       case id
       when Array, Hash
@@ -192,14 +194,13 @@ module ActiveRecord
         relation = relation.where(table[primary_key].eq(id)) if id
       end
 
-      relation.first ? true : false
+      connection.select_value(relation.to_sql) ? true : false
     end
 
     protected
 
     def find_with_associations
-      including = (@eager_load_values + @includes_values).uniq
-      join_dependency = ActiveRecord::Associations::JoinDependency.new(@klass, including, [])
+      join_dependency = construct_join_dependency_for_association_find
       relation = construct_relation_for_association_find(join_dependency)
       rows = connection.select_all(relation.to_sql, 'SQL', relation.bind_values)
       join_dependency.instantiate(rows)
@@ -207,6 +208,11 @@ module ActiveRecord
       []
     end
 
+    def construct_join_dependency_for_association_find
+      including = (@eager_load_values + @includes_values).uniq
+      ActiveRecord::Associations::JoinDependency.new(@klass, including, [])
+    end
+
     def construct_relation_for_association_calculations
       including = (@eager_load_values + @includes_values).uniq
       join_dependency = ActiveRecord::Associations::JoinDependency.new(@klass, including, arel.froms.first)