# File lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 646 def references(*args) options = args.extract_options! polymorphic = options.delete(:polymorphic) args.each do |col| @base.add_column(@table_name, "#{col}_id", :integer, options) @base.add_column(@table_name, "#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) unless polymorphic.nil? end end