嵌套有许多通过插件和命名范围

Question

我有一个用户模型（：姓名，：密码，：电子邮件），和事件模型（：姓名，：等）和兴趣模型（：名称）[>所有奇异<]

然后我创建了两个连接表 - > UsersInterests和EventsInterests;各自不含有主键和分别仅包括的USER_ID / interest_id和的event_id / interest_id。 [>复数<]

我的模型使用嵌套有许多通过插件

user.rb => has_many :users_interests
 has_many :interests, :through => :users_interests
 has_many :events_interests, :through => :interests
 has_many :events, :through => :events_interests

event.rb => has_many :events_interests
  has_many :interests, :through => :events_interests
     has_many :users_interests, :through => :interests
  has_many :users, :through => :users_interests

interest.rb => has_and_belongs_to_many :users
               has_and_belongs_to_many :events

events_interests.rb => belongs_to :interests
                    belongs_to :events
users_interests.rb => belongs_to :users
                   belongs_to :interests

Whew..ok所以我想创造一个named_scope发现所有的事件与特定用户共享的兴趣。下面是一些代码有人帮我。

named_scope :shares_interest_with_users, lambda {|user|
{ :joins => :users_interests,
  :conditions => {:users_interests => {:user_id => user}}
   }}

当我从控制器运行=>

@user = User.find(1) 
@events = Event.shares_interest_with_user(@user)

我得到错误：

uninitialized constant Event::EventsInterest

任何人都可以看到我搞砸了？

Answer 1

您必须命名沿途一些错误。我一眼说你有一个名为不正确的文件或类。记住型号名称必须始终是奇异的，无论是在文件和类名，否则Rails会不会进行连接。你的问题的另一个原因是，参数belongs_to的也必须是单数。就算你得到了正确的事情，当你运行了一个名为范围中的利益关系HABTM与用户会抛出一个错误。

我可以用下面的模型来解决您的错误。

<强> user.rb

class User < ActiveRecord::Base
has_many :users_interests
  has_many :interests, :through => :users_interests
  has_many :events_interests, :through => :interests
  has_many :events, :through => :events_interests
end

<强> users_interest.rb

class UsersInterest < ActiveRecord::Base
  belongs_to :user
  belongs_to :interest
end

<强> interest.rb

class Interest < ActiveRecord::Base 
  has_many :users,:through => :users_interests
  has_many :users_interests
  has_many :events_interests
  has_many :events, :through => :events_interests
end

** events_interest.rb

class EventsInterest <ActiveRecord::Base
  belongs_to :interest
  belongs_to :event
end

<强> event.rb

class Event <ActiveRecord::Base 
  has_many :events_interests
  has_many :interests, :through => :events_interests
  has_many :users_interests, :through => :interests
  has_many :users, :through => :users_interests


  named_scope :shares_interest_with_users, lambda {|user|
    { :joins => :users_interests,
      :conditions => {:users_interests => {:user_id => user}}
    }
  }

end