moved sql related code to its own engine area

Conflicts:

	lib/arel/engine.rb
	lib/arel/extensions/object.rb
	lib/arel/predicates.rb
	lib/arel/primitives/attribute.rb
	lib/arel/primitives/expression.rb
	lib/arel/primitives/value.rb
	lib/arel/relations/operations/join.rb
	lib/arel/relations/relation.rb
	lib/arel/relations/utilities/externalization.rb
	lib/arel/relations/utilities/nil.rb
	lib/arel/relations/writes/delete.rb
	lib/arel/relations/writes/insert.rb
	lib/arel/relations/writes/update.rb
	spec/arel/unit/relations/skip_spec.rb
	spec/arel/unit/relations/take_spec.rb
	spec/spec_helper.rb

12 files changed, 1 insertions, 160 deletions

diff --git a/lib/arel/relations/array.rb b/lib/arel/relations/array.rb
deleted file mode 100644
index dac65abbc2..0000000000
--- a/lib/arel/relations/array.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-module Arel
-  class Array < Relation
-    include Recursion::BaseCase
-
-    def initialize(array, attribute_names)
-      @array, @attribute_names = array, attribute_names
-    end
-
-    def attributes
-      @attributes ||= @attribute_names.collect do |name|
-        Attribute.new(self, name.to_sym)
-      end
-    end
-
-    def call(connection = nil)
-      @array.collect { |row| attributes.zip(row).to_hash }
-    end
-  end
-end
\ No newline at end of file
diff --git a/lib/arel/relations/operations/alias.rb b/lib/arel/relations/operations/alias.rb
index 8ed33fc597..67837f6a75 100644
--- a/lib/arel/relations/operations/alias.rb
+++ b/lib/arel/relations/operations/alias.rb
@@ -1,6 +1,5 @@
 module Arel
   class Alias < Compound
-    include Recursion::BaseCase
     attributes :relation
     deriving :initialize
     alias_method :==, :equal?
diff --git a/lib/arel/relations/operations/join.rb b/lib/arel/relations/operations/join.rb
index 8fe89358d8..8e19254378 100644
--- a/lib/arel/relations/operations/join.rb
+++ b/lib/arel/relations/operations/join.rb
@@ -9,22 +9,6 @@ module Arel
       @join_sql, @relation1, @relation2, @predicates = join_sql, relation1, relation2, predicates
     end
 
-    def table_sql(formatter = Sql::TableReference.new(self))
-      relation1.externalize.table_sql(formatter)
-    end
-
-    def joins(environment, formatter = Sql::TableReference.new(environment))
-      @joins ||= begin
-        this_join = [
-          join_sql,
-          relation2.externalize.table_sql(formatter),
-          ("ON" unless predicates.blank?),
-          (ons + relation2.externalize.wheres).collect { |p| p.bind(environment).to_sql(Sql::WhereClause.new(environment)) }.join(' AND ')
-        ].compact.join(" ")
-        [relation1.joins(environment), this_join, relation2.joins(environment)].compact.join(" ")
-      end
-    end
-
     def attributes
       @attributes ||= (relation1.externalize.attributes +
         relation2.externalize.attributes).collect { |a| a.bind(self) }
diff --git a/lib/arel/relations/relation.rb b/lib/arel/relations/relation.rb
index ef295dfdd7..20badaf165 100644
--- a/lib/arel/relations/relation.rb
+++ b/lib/arel/relations/relation.rb
@@ -6,32 +6,6 @@ module Arel
       Session.new
     end
 
-    def count
-      @count = "COUNT(*) AS count_all"
-    end
-
-    def to_sql(formatter = Sql::SelectStatement.new(self))
-      formatter.select select_sql, self
-    end
-    alias_method :to_s, :to_sql
-
-    def select_sql
-      [
-        "SELECT  #{@count} #{attributes.collect { |a| a.to_sql(Sql::SelectClause.new(self)) }.join(', ') unless @count}",
-        "FROM       #{table_sql(Sql::TableReference.new(self))}",
-        (joins(self)                                                                                    unless joins(self).blank? ),
-        ("WHERE     #{wheres   .collect { |w| w.to_sql(Sql::WhereClause.new(self)) }.join("\n\tAND ")}" unless wheres.blank?      ),
-        ("GROUP BY  #{groupings.collect { |g| g.to_sql(Sql::GroupClause.new(self)) }.join(', ')}"       unless groupings.blank?   ),
-        ("ORDER BY  #{orders   .collect { |o| o.to_sql(Sql::OrderClause.new(self)) }.join(', ')}"       unless orders.blank?      ),
-        ("LIMIT     #{taken}"                                                                           unless taken.blank?       ),
-        ("OFFSET    #{skipped}"                                                                         unless skipped.blank?     )
-      ].compact.join("\n")
-    end
-
-    def inclusion_predicate_sql
-      "IN"
-    end
-
     def call
       engine.read(self)
     end
@@ -44,10 +18,6 @@ module Arel
       self
     end
 
-    def christener
-      @christener ||= Sql::Christener.new
-    end
-
     module Enumerable
       include ::Enumerable
 
@@ -155,7 +125,7 @@ module Arel
       def orders;                 []  end
       def inserts;                []  end
       def groupings;              []  end
-      def joins(formatter = nil); nil end
+      def joins(formatter = nil); nil end # FIXME
       def taken;                  nil end
       def skipped;                nil end
     end
diff --git a/lib/arel/relations/table.rb b/lib/arel/relations/table.rb
deleted file mode 100644
index 0433abbbb2..0000000000
--- a/lib/arel/relations/table.rb
+++ /dev/null
@@ -1,36 +0,0 @@
-module Arel
-  class Table < Relation
-    include Recursion::BaseCase
-
-    cattr_accessor :engine
-    attr_reader :name, :engine
-    hash_on :name
-
-    def initialize(name, engine = Table.engine)
-      @name, @engine = name.to_s, engine
-    end
-
-    def attributes
-      @attributes ||= columns.collect do |column|
-        Attribute.new(self, column.name.to_sym)
-      end
-    end
-
-    def column_for(attribute)
-      has_attribute?(attribute) and columns.detect { |c| c.name == attribute.name.to_s }
-    end
-
-    def columns
-      @columns ||= engine.columns(name, "#{name} Columns")
-    end
-
-    def reset
-      @attributes = @columns = nil
-    end
-
-    def ==(other)
-      Table      === other and
-      name       ==  other.name
-    end
-  end
-end
diff --git a/lib/arel/relations/utilities.rb b/lib/arel/relations/utilities.rb
index 454d455359..fbd949ef0c 100644
--- a/lib/arel/relations/utilities.rb
+++ b/lib/arel/relations/utilities.rb
@@ -1,5 +1,3 @@
 require 'arel/relations/utilities/compound'
-require 'arel/relations/utilities/recursion'
 require 'arel/relations/utilities/nil'
 require 'arel/relations/utilities/externalization'
-require 'arel/relations/utilities/recursion'
\ No newline at end of file
diff --git a/lib/arel/relations/utilities/externalization.rb b/lib/arel/relations/utilities/externalization.rb
index 3b9b2296dc..bd067f2304 100644
--- a/lib/arel/relations/utilities/externalization.rb
+++ b/lib/arel/relations/utilities/externalization.rb
@@ -2,24 +2,14 @@ module Arel
   class Externalization < Compound
     attributes :relation
     deriving :initialize, :==
-    include Recursion::BaseCase
 
     def wheres
       []
     end
 
-    def table_sql(formatter = Sql::TableReference.new(relation))
-      formatter.select relation.select_sql, self
-    end
-
     def attributes
       @attributes ||= relation.attributes.collect(&:to_attribute).collect { |a| a.bind(self) }
     end
-
-    # REMOVEME
-    def name
-      relation.name + '_external'
-    end
   end
 
   class Relation
diff --git a/lib/arel/relations/utilities/nil.rb b/lib/arel/relations/utilities/nil.rb
index 56cf395d2c..6a9d678c45 100644
--- a/lib/arel/relations/utilities/nil.rb
+++ b/lib/arel/relations/utilities/nil.rb
@@ -3,8 +3,5 @@ require 'singleton'
 module Arel
   class Nil < Relation
     include Singleton
-
-    def table_sql(formatter = nil); '' end
-    def name; '' end
   end
 end
diff --git a/lib/arel/relations/utilities/recursion.rb b/lib/arel/relations/utilities/recursion.rb
deleted file mode 100644
index 848b059507..0000000000
--- a/lib/arel/relations/utilities/recursion.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-module Arel
-  module Recursion
-    module BaseCase
-      def table
-        self
-      end
-
-      def table_sql(formatter = Sql::TableReference.new(self))
-        formatter.table self
-      end
-    end
-  end
-end
\ No newline at end of file
diff --git a/lib/arel/relations/writes/delete.rb b/lib/arel/relations/writes/delete.rb
index 0a04454e7f..a94067c7fa 100644
--- a/lib/arel/relations/writes/delete.rb
+++ b/lib/arel/relations/writes/delete.rb
@@ -3,15 +3,6 @@ module Arel
     attributes :relation
     deriving :initialize, :==
 
-    def to_sql(formatter = nil)
-      [
-        "DELETE",
-        "FROM #{table_sql}",
-        ("WHERE #{wheres.collect(&:to_sql).join('\n\tAND ')}" unless wheres.blank?  ),
-        ("LIMIT #{taken}"                                     unless taken.blank?    ),
-      ].compact.join("\n")
-    end
-
     def call
       engine.delete(self)
     end
diff --git a/lib/arel/relations/writes/insert.rb b/lib/arel/relations/writes/insert.rb
index d05bd9cdc8..6d85e9769a 100644
--- a/lib/arel/relations/writes/insert.rb
+++ b/lib/arel/relations/writes/insert.rb
@@ -7,15 +7,6 @@ module Arel
       @relation, @record = relation, record.bind(relation)
     end
 
-    def to_sql(formatter = nil)
-      [
-        "INSERT",
-        "INTO #{table_sql}",
-        "(#{record.keys.map { |key| engine.quote_column_name(key.name) }.join(', ')})",
-        "VALUES (#{record.map { |key, value| key.format(value) }.join(', ')})"
-      ].join("\n")
-    end
-
     def call
       engine.create(self)
     end
diff --git a/lib/arel/relations/writes/update.rb b/lib/arel/relations/writes/update.rb
index fd0aadb479..e647218a80 100644
--- a/lib/arel/relations/writes/update.rb
+++ b/lib/arel/relations/writes/update.rb
@@ -7,17 +7,6 @@ module Arel
       @relation, @assignments = relation, assignments
     end
 
-    def to_sql(formatter = nil)
-      [
-        "UPDATE #{table_sql} SET",
-        assignments.collect do |attribute, value|
-          "#{engine.quote_column_name(attribute.name)} = #{attribute.format(value)}"
-        end.join(",\n"),
-        ("WHERE #{wheres.map(&:to_sql).join('\n\tAND ')}"  unless wheres.blank?  ),
-        ("LIMIT #{taken}"                                      unless taken.blank?    )
-      ].join("\n")
-    end
-
     def call
       engine.update(self)
     end