ついカッとなってやった、今は反省している。後で翻訳する。 http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html#M002132 Nested Attributes Nested attributes allow you to save attributes on associated records through the parent. By default nested attribute updating is turned off, you can enable it using the accepts_nested_attributes_for class method. When you enable nested attributes an attribute wr