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我试图在 Post 模型中使用 viewer_ids 来保存 user_ids，并在 User 模型中使用 viewer_ids 来保存被查看的 post_ids。使用 Rspec 进行测试以添加/删除和访问来自用户的关系时，它工作得很好。但是当我使用 RABL 来查看帖子时——在嵌入用户数据的情况下——它会变得混乱并给我一个模糊的关系。

#Post class
belongs_to :user
has_and_belongs_to_many :viewers, class_name: 'User', inverse_of: :viewed  

#User class
has_many :users
has_and_belongs_to_many :viewed, class_name: 'Post', inverse_of: :viewers

Mongoid::Errors::AmbiguousRelationship in Posts#show

Problem:
Ambiguous relations :posts, :viewed defined on User.
Summary:
When Mongoid attempts to set an inverse document of a relation in memory, it needs to know which relation it belongs to. When setting :user, Mongoid looked on the class Post for a matching relation, but multiples were found that could potentially match: :posts, :viewed.
Resolution:
On the :user relation on Post you must add an :inverse_of option to specify the exact relationship on User that is the opposite of :user.

那么问题是什么，我正在定义关系和它们的倒数。是否不可能有与关系相反的不同数据？

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1 回答 1

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问题是在模型上具有同一类的多个关系时。因此，一旦添加了 nn，每边就有 2 个用户关系和 2 个帖子关系。

#Post class
belongs_to :user, inverse_of: :posts
has_and_belongs_to_many :viewers, class_name: 'User', inverse_of: :viewed  

#User class
has_many :posts, inverse_of: :user
has_and_belongs_to_many :viewed, class_name: 'Post', inverse_of: :viewers

Thanks to Duran for his clearing this up https://jira.mongodb.org/browse/MONGOID-2923?focusedCommentId=982950&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-982950

于 2013-03-23T12:04:09.140 回答