ruby-on-rails - 在哪里使用依赖 : :destroy

Question

假设 User 有很多 Receipt 并且我希望 Receipt 的所有实例在父 User 实例被删除。

写法有什么区别:

(1) 在User模型中，has_many :receipts, dependent: :destroy

(2) 在Receipt模型中，belongs_to :user, dependent: :destroy

有什么建议吗？

Answer 1

(1) In User model, has_many :receipts, dependent: :destroy

如果用户被销毁，那么其关联的收据也将被销毁。

(2) In Receipt model, belongs_to :user, dependent: :destroy

如果收据被销毁，那么它的父用户将被销毁，而不是其他相关的收据不会被销毁但会被孤立。根据docs

This dependent: option should not be specified when belongs_to is used inconjunction with a has_many relationship on another class because ofthe potential to leave orphaned records behind.