Ruby on rails 有很多：通过：外键

我的模型是这样的：

class Post < ActiveRecord::Base
  has_many :aspect_visibilities, :as => :shareable, :primary_key => :guid, :foreign_key => :shareable_guid
  has_many :aspects, :through => :aspect_visibilities
end

class AspectVisibility < ActiveRecord::Base
  belongs_to :aspect
  validates_presence_of :aspect

  belongs_to :shareable, :polymorphic => true, :primary_key => :guid, :foreign_key => :shareable_guid 
  validates_presence_of :shareable
end

class Aspect < ActiveRecord::Base
  has_many :aspect_visibilities
  has_many :posts, :through => :aspect_visibilities, :source => :shareable, :source_type => 'Post'
end

class Post < ActiveRecord::Base
  set_primary_key :guid
  [...]
end

class Post：可共享，：主键=>：guid，：外键=>：可共享的\u guid
有很多：方面，：通过=>：方面
结束
类AspectVisibilitytrue，：主键=>：guid，：外键=>：可共享\U guid
验证是否存在：可共享
结束
类方面:aspect\u可见性，：source=>:shareable，：source\u type=>'Post'
结束

我的问题是，当我将帖子插入一个方面时，帖子的id作为帖子的键插入到AspectVisibility中。但实际上应该插入Post的guid

我见过这样的解决方案：

class Post < ActiveRecord::Base
  has_many :aspect_visibilities, :as => :shareable, :primary_key => :guid, :foreign_key => :shareable_guid
  has_many :aspects, :through => :aspect_visibilities
end

class AspectVisibility < ActiveRecord::Base
  belongs_to :aspect
  validates_presence_of :aspect

  belongs_to :shareable, :polymorphic => true, :primary_key => :guid, :foreign_key => :shareable_guid 
  validates_presence_of :shareable
end

class Aspect < ActiveRecord::Base
  has_many :aspect_visibilities
  has_many :posts, :through => :aspect_visibilities, :source => :shareable, :source_type => 'Post'
end

class Post < ActiveRecord::Base
  set_primary_key :guid
  [...]
end

class Post

但我一般不想更改POST的外键，只想更改AspectVisibility关联

有人能告诉我怎么做吗

---

谢谢

我尝试了同样的方法，文章的guid作为可共享的guid插入到方面可见性中。这就是我正在做的

>aspect = Aspect.create(:name => "name")
>#<Aspect id: 1, name: "name", created_at: "2011-11-24 18:08:53", updated_at: "2011-11-    24 18:08:53">
> post = Post.create(:guid => 'guid', :name => "name")
>#<Post id: 1, guid: "guid", name: "name", created_at: "2011-11-24 18:09:26", updated_at: "2011-11-24 18:09:26">
> aspect.posts << post
>[#<Post id: 1, guid: "guid", name: "name", created_at: "2011-11-24 18:09:26", updated_at: "2011-11-24 18:09:26">]
>aspect.aspect_visibilities
>[#<AspectVisibility id: 1, guid: nil, shareable_type: "Post", **shareable_guid: "guid"**, aspect_id: 1, created_at: "2011-11-24 18:09:48", updated_at: "2011-11-24 18:09:48">]

>aspect=aspect.create（：name=>“name”）
>#
>post=post.create（：guid=>guid'，：name=>name）
>#
>aspect.posts[#]
>aspect.aspect\u可视性
>[#]

---

请注意aspect_可见性中可共享的_guid的值。它被设置为post的guid，而不是id。

如果您为示例中的所有模型发布代码，则会有所帮助