refactored session's interaction with engine/connection

  - follows law of demeter
  - Table.engine uses AR::Base adapter

5 files changed, 20 insertions, 4 deletions

diff --git a/lib/active_relation/relations/deletion.rb b/lib/active_relation/relations/deletion.rb
index f3d81baf27..c5906e8bc8 100644
--- a/lib/active_relation/relations/deletion.rb
+++ b/lib/active_relation/relations/deletion.rb
@@ -12,6 +12,10 @@ module ActiveRelation
       ].compact.join("\n")
     end
     
+    def call(connection = engine.connection)
+      connection.delete(to_sql)
+    end
+    
     def ==(other)
       self.class  == other.class    and
       relation    == other.relation
diff --git a/lib/active_relation/relations/insertion.rb b/lib/active_relation/relations/insertion.rb
index 16fe3d5f46..036db1a319 100644
--- a/lib/active_relation/relations/insertion.rb
+++ b/lib/active_relation/relations/insertion.rb
@@ -15,6 +15,10 @@ module ActiveRelation
       ].join("\n")
     end
     
+    def call(connection = engine.connection)
+      connection.insert(to_sql)
+    end
+    
     def ==(other)
       self.class  == other.class    and
       relation    == other.relation and
diff --git a/lib/active_relation/relations/relation.rb b/lib/active_relation/relations/relation.rb
index f9823bf92d..69935a7be0 100644
--- a/lib/active_relation/relations/relation.rb
+++ b/lib/active_relation/relations/relation.rb
@@ -115,6 +115,10 @@ module ActiveRelation
       ].compact.join("\n"), self.alias
     end
     alias_method :to_s, :to_sql
+    
+    def call(connection = engine.connection)
+      connection.select_all(to_sql)
+    end
         
     def attribute_for_name(name)
       attributes.detect { |a| a.alias_or_name.to_s == name.to_s }
diff --git a/lib/active_relation/relations/update.rb b/lib/active_relation/relations/update.rb
index c50919af3e..0914cda035 100644
--- a/lib/active_relation/relations/update.rb
+++ b/lib/active_relation/relations/update.rb
@@ -16,6 +16,10 @@ module ActiveRelation
       ].join("\n")
     end
     
+    def call(connection = engine.connection)
+      connection.update(to_sql)
+    end
+    
     def ==(other)
       self.class  == other.class    and
       relation    == other.relation and
diff --git a/lib/active_relation/sessions/session.rb b/lib/active_relation/sessions/session.rb
index 4bdbe69978..fe917a0e4d 100644
--- a/lib/active_relation/sessions/session.rb
+++ b/lib/active_relation/sessions/session.rb
@@ -25,22 +25,22 @@ module ActiveRelation
     
     module CRUD
       def create(insert)
-        insert.engine.insert(insert.to_sql)
+        insert.call(insert.engine.connection)
       end
       
       def read(select)
         @read ||= Hash.new do |hash, select|
-          hash[select] = select.engine.select_all(select.to_sql)
+          hash[select] = select.call(select.engine.connection)
         end
         @read[select]
       end
       
       def update(update)
-        update.engine.update(update.to_sql)
+        update.call(update.engine.connection)
       end
       
       def delete(delete)
-        delete.engine.delete(delete.to_sql)
+        delete.call(delete.engine.connection)
       end
     end
     include CRUD