automatically add primary key to #select_limited_ids_list order by clause for databases that require order columns in the distinct statements (postgresql) [Rick]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5292 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 10 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 949b8f7951..b753c248c5 100755
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -56,6 +56,12 @@ module ActiveRecord
         false
       end
 
+      # Does this adapter require the order columns to be in the select clause
+      # of a DISTINCT query?  This is +false+ in all adapters except postgresql.
+      def requires_order_columns_in_distinct_clause?
+        false
+      end
+
       def reset_runtime #:nodoc:
         rt, @runtime = @runtime, 0
         rt
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 975768a758..e5e098a4e1 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -111,6 +111,10 @@ module ActiveRecord
         63
       end
 
+      def requires_order_columns_in_distinct_clause?
+        true
+      end
+
       # QUOTING ==================================================
 
       def quote(value, column = nil)