导轨:依赖=>:destroy VS :dependent =>:删除所有 [英] Rails :dependent => :destroy VS :dependent => :delete_all

问题描述

在 Rails 指南中是这样描述的:

In rails guides it's described like this:

如果对象与 :dependent =>:destroy，如果它们与 :dependent => 关联则删除:delete_all

Objects will be in addition destroyed if they’re associated with :dependent => :destroy, and deleted if they’re associated with :dependent => :delete_all

好的，很酷.但是被销毁和被删除有什么区别呢?我都试过了，它似乎做同样的事情.

Right, cool. But what's the difference between being destroyed and being deleted? I tried both and it seems to do the same thing.

推荐答案

区别在于回调.

:delete_all 直接在您的应用程序中生成并通过 SQL 删除:

The :delete_all is made directly in your application and deletes by SQL :

DELETE * FROM users where compagny_id = XXXX

使用 :destroy，您的所有孩子都会被实例化.所以，如果你不能销毁它，或者如果每个都有自己的 :dependent，它的回调可以被调用.

With the :destroy, there is an instantiation of all of your children. So, if you can't destroy it or if each has their own :dependent, its callbacks can be called.

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