most in memory operations save join and group

Conflicts:

	lib/arel/algebra/extensions/object.rb
	lib/arel/algebra/primitives/value.rb
	lib/arel/engines/memory/relations.rb
	lib/arel/engines/sql/formatters.rb
	lib/arel/engines/sql/primitives.rb
	spec/arel/unit/relations/alias_spec.rb
	spec/arel/unit/relations/array_spec.rb
	spec/arel/unit/relations/order_spec.rb

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/arel/engines/sql/primitives.rb b/lib/arel/engines/sql/primitives.rb
index 6f89723afe..9e9143ac0f 100644
--- a/lib/arel/engines/sql/primitives.rb
+++ b/lib/arel/engines/sql/primitives.rb
@@ -24,6 +24,20 @@ module Arel
       object.to_sql(Sql::Value.new(relation))
     end
   end
+  
+  class Ordering
+    def to_sql(formatter = Sql::OrderClause.new(relation))
+      formatter.ordering self
+    end
+  end
+  
+  class Ascending < Ordering
+    def direction_sql; 'ASC' end
+  end
+  
+  class Descending < Ordering
+    def direction_sql; 'DESC' end
+  end
 
   class Expression < Attribute
     def to_sql(formatter = Sql::SelectClause.new(relation))