1 files changed, 9 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 2c76dd1518..10329de5f4 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -23,6 +23,9 @@ module ActiveRecord
     class ChangeColumnDefinition < Struct.new(:column, :name) #:nodoc:
     end
 
+    class PrimaryKeyDefinition < Struct.new(:name) # :nodoc:
+    end
+
     class ForeignKeyDefinition < Struct.new(:from_table, :to_table, :options) #:nodoc:
       def name
         options[:name]
@@ -207,6 +210,7 @@ module ActiveRecord
         @columns_hash = {}
         @indexes = {}
         @foreign_keys = {}
+        @primary_keys = nil
         @native = types
         @temporary = temporary
         @options = options
@@ -214,6 +218,11 @@ module ActiveRecord
         @name = name
       end
 
+      def primary_keys(name = nil) # :nodoc:
+        @primary_keys = PrimaryKeyDefinition.new(name) if name
+        @primary_keys
+      end
+
       # Returns an array of ColumnDefinition objects for the columns of the table.
       def columns; @columns_hash.values; end