如何使用 has_many 销毁记录，:dependent => ：破坏
我在几个插件的帮助下构建了一个 Rail 3 AuditLog，这些插件将数据存储在 AuditLog 表中，并具有以下用于标识的字段（feeded_id、feeded_type）。
所以就我而言，我有一个包含很多照片的相册。
class PhotoAlbum < ActiveRecord::Base
has_many :photos, :dependent => :destroy
当我删除相册（id = 2）时，这可以很好地删除所有关联的照片，但它不会从 AuditLog 中删除如下所示的项目：（feeded_id = 2，feeded_type = PhotoAlbum）
鉴于 AuditLog 表不没有“photo_album_id”列，并且不能，有没有办法设置依赖 >当删除相册时，使用 Rails Destory 删除 AuditLog 中的所有关联项目？
谢谢，我知道这个比大多数都复杂一点。感谢您阅读它！
I've built a Rail 3 AuditLog with the help of a few plugins, that store data in an AuditLog Table with the following fields for identification (feeded_id, feeded_type)
So in my case, I have a photoalbum that has_many photos.
class PhotoAlbum < ActiveRecord::Base
has_many :photos, :dependent => :destroy
when I delete a photoalbum (id=2) this works very well to delete all associated photos, but it doesn't delete items from the AuditLog that are like this: (feeded_id = 2, feeded_type = PhotoAlbum)
Given that the AuditLog table doesn't have a "photo_album_id" column, and can't, is there a way to setup a dependent > Destory with Rails to delete all associated items in teh AuditLog when a PhotoAlbum is deleted?
Thanks, I know this one's a little more complicated than most. Thanks for reading through it!
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的组合
我认为您正在寻找的是
belongs_to :feeded, :polymorphic => true在您的审核日志类中，并且
has_many :logs, :as => ：喂养，：依赖=> :destroy在你的 PhotoAlbum 类中。
如果您没有一个类来表示您的审核日志，您应该能够将
belongs_to添加到现有类中（也许在您的插件中？）。我对 :as => 不是 100% 确定:feeded 选项，您必须正确命名该符号，我不确定 ActiveRecord 会期望什么，但是
belongs_to关系将查找 feeded_id 和 feeded_type，因此当“父”对象是 PhotoAlbum 时它将正确加入photo_album.id =audit_logs.feeded_id ANDaudit_logs.feeded_type = 'PhotoAlbum'。由于这不需要对数据库进行任何更改，因此所有现有代码应该继续工作。您可以在此处阅读关联选项。
I think what you are looking for is the combination of
belongs_to :feeded, :polymorphic => truein your Audit log class and
has_many :logs, :as => :feeded, :dependent => :destroyin your PhotoAlbum class.
If you do not have a class to represent your audit log, you should be able to add the
belongs_toto the existing class (in your plugins perhaps?).I'm not 100% sure about the :as => :feeded option, you will have to name that symbol correctly and I am not sure what ActiveRecord will expect, but the
belongs_torelationship will look for feeded_id and feeded_type, so when the 'parent' object is a PhotoAlbum it will join correctly onphoto_album.id = audit_logs.feeded_id AND audit_logs.feeded_type = 'PhotoAlbum'. Since this doesn't require any changes to your database, all your existing code should continue to work.You can read up on the options for associations here.