1 files changed, 10 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index c1f44b51f0..4edb64c2c0 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -208,6 +208,10 @@ module ActiveRecord
         true
       end
       
+      def supports_primary_key? #:nodoc:
+        true
+      end
+
       def supports_savepoints? #:nodoc:
         true
       end
@@ -550,6 +554,12 @@ module ActiveRecord
         keys.length == 1 ? [keys.first, nil] : nil
       end
 
+      # Returns just a table's primary key
+      def primary_key(table)
+        pk_and_sequence = pk_and_sequence_for(table)
+        pk_and_sequence && pk_and_sequence.first
+      end
+
       def case_sensitive_equality_operator
         "= BINARY"
       end