primary_keys

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 590
      def primary_keys(table_name) # :nodoc:
        raise ArgumentError unless table_name.present?

        schema, name = extract_schema_qualified_name(table_name)

        select_values(          SELECT column_name          FROM information_schema.key_column_usage          WHERE constraint_name = 'PRIMARY'            AND table_schema = #{quote(schema)}            AND table_name = #{quote(name)}          ORDER BY ordinal_position.strip_heredoc, 'SCHEMA')
      end