reorganizing classes

2 files changed, 70 insertions, 10 deletions

diff --git a/lib/arel/algebra/relations/relation.rb b/lib/arel/algebra/relations/relation.rb
index 17a2cf3190..3f6151e27b 100644
--- a/lib/arel/algebra/relations/relation.rb
+++ b/lib/arel/algebra/relations/relation.rb
@@ -1,5 +1,7 @@
 module Arel
   module Relation
+    @@connection_tables_primary_keys = {}
+
     attr_reader :count
 
     def session
@@ -18,6 +20,74 @@ module Arel
       self
     end
 
+    def externalize
+      @externalized ||= externalizable?? Externalization.new(self) : self
+    end
+
+    def externalizable?
+      false
+    end
+
+    def compiler
+      @compiler ||=  begin
+        "Arel::SqlCompiler::#{engine.adapter_name}Compiler".constantize.new(self)
+      rescue
+        Arel::SqlCompiler::GenericCompiler.new(self)
+      end
+    end
+
+    def to_sql(formatter = Sql::SelectStatement.new(self))
+      formatter.select compiler.select_sql, self
+    end
+
+    def christener
+      @christener ||= Sql::Christener.new
+    end
+
+    def inclusion_predicate_sql
+      "IN"
+    end
+
+    def exclusion_predicate_sql
+      "NOT IN"
+    end
+
+    def primary_key
+      connection_id = engine.connection.object_id
+      if @@connection_tables_primary_keys[connection_id] && @@connection_tables_primary_keys[connection_id].has_key?(table.name)
+        @@connection_tables_primary_keys[connection_id][table.name]
+      else
+        @@connection_tables_primary_keys[connection_id] ||= {}
+        @@connection_tables_primary_keys[connection_id][table.name] = engine.connection.primary_key(table.name)
+      end
+    end
+
+    protected
+
+      def from_clauses
+        sources.blank? ? table_sql(Sql::TableReference.new(self)) : sources
+      end
+
+      def select_clauses
+        attributes.collect { |a| a.to_sql(Sql::SelectClause.new(self)) }
+      end
+
+      def where_clauses
+        wheres.collect { |w| w.to_sql(Sql::WhereClause.new(self)) }
+      end
+
+      def group_clauses
+        groupings.collect { |g| g.to_sql(Sql::GroupClause.new(self)) }
+      end
+
+      def having_clauses
+        havings.collect { |g| g.to_sql(Sql::HavingClause.new(self)) }
+      end
+
+      def order_clauses
+        orders.collect { |o| o.to_sql(Sql::OrderClause.new(self)) }
+      end
+
     module Enumerable
       include ::Enumerable
 
diff --git a/lib/arel/algebra/relations/utilities/externalization.rb b/lib/arel/algebra/relations/utilities/externalization.rb
index c7a7d9ca78..815e1e0aa7 100644
--- a/lib/arel/algebra/relations/utilities/externalization.rb
+++ b/lib/arel/algebra/relations/utilities/externalization.rb
@@ -12,14 +12,4 @@ module Arel
       @attributes ||= Header.new(relation.attributes.map { |a| a.to_attribute(self) })
     end
   end
-
-  module Relation
-    def externalize
-      @externalized ||= externalizable?? Externalization.new(self) : self
-    end
-
-    def externalizable?
-      false
-    end
-  end
 end