Question

我有一些使用MongoDB，Mongoid mapper和devise的rails应用程序。 Аuthorized用户可以创建，编辑，删除帖子（脚手架）并评论此帖子。我采取了Ryan Bates截屏的评论模型示例，238集“Mongoid”。

comment.rb

class Comment
  include Mongoid::Document
  field :name
  field :content
  embedded_in :post, :inverse_of => :comments
end

post.rb

class Post
      include Mongoid::Document
      field :name
      field :content
      validates_presence_of :name
      embeds_many :comments
    end

user.rb

class User
  include Mongoid::Document
  # Include default devise modules. Others available are:
  # :token_authenticatable, :encryptable, :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
    :recoverable, :rememberable, :trackable, :validatable

  field :username

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me

  has_many :comments
  references_many :post

end

但是当我尝试注册新用户时，在注册表单中按“注册”，我看到了这个错误

Mongoid::Errors::MixedRelations in Devise::RegistrationsController#create

Referencing a(n) Comment document from the User document via a relational association is not allowed since the Comment is embedded.

我用Mysql db开始这个应用程序，然后决定进入mongo。我的错误在哪里？

Answer 1

由于评论嵌入在帖子中，您应该有用户引用帖子。尝试删除用户中的has_many :comments。

Mongoid与设计的关系

1 个答案: