Rails - 模型疑问

发布于 2024-11-09 05:16:33 字数 866 浏览 6 评论 0原文

鉴于我有这样的模型：

class Person
  has_many :owned_groups, :class_name => "Group", :foreign_key => :owner_id
  has_many :owned_group_memberships, :through => :owned_groups, 
              :source => :group_memberships 

  has_many :group_memberships, :foreign_key => "member_id"
  has_many :groups, :through => :group_memberships

end

class GroupMembership
  belongs_to :member, :class_name => 'Person'
  belongs_to :group
end

class Group
  belongs_to :owner, :class_name => "Person"
  has_many :group_memberships
  has_many :members, :through => :group_memberships
end

How can I access the members a group has?我总是做 @group.members 或类似的事情，给我一个错误，说在模型中找不到关系。

提前致谢。

##EDIT##

我收到的错误是：无法在模型组中找到关联“group_memberships”

原文

Given the fact that I have models like this:

class Person
  has_many :owned_groups, :class_name => "Group", :foreign_key => :owner_id
  has_many :owned_group_memberships, :through => :owned_groups, 
              :source => :group_memberships 

  has_many :group_memberships, :foreign_key => "member_id"
  has_many :groups, :through => :group_memberships

end

class GroupMembership
  belongs_to :member, :class_name => 'Person'
  belongs_to :group
end

class Group
  belongs_to :owner, :class_name => "Person"
  has_many :group_memberships
  has_many :members, :through => :group_memberships
end

How can I access the members a group has? Always I do @group.members or things like that, gives me an error saying that the relation can't be found in the model.

Thanks in advance.

##EDIT##

The error I'm getting is: Could not find the association "group_memberships" in model Group

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夜唯美灬不弃 2024-11-16 05:16:33

我在我正在开发的网站上做了类似的事情，但关联与你的做法有点不同，但也许会有帮助。我认为您需要使用 has_and_belongs_to_many 关联来加入多对多关联。

在我的数据库中，我有 Users、Members 和 UsersMembers

您不需要创建 UsersMembers 模型（在您的情况下为 GroupMembership），但您确实需要一个数据库表来链接这两者。

#Migration
    create_table :bands_users, :id => false, :force => true do |t|
      t.integer :band_id,       :null => false
      t.integer :user_id,       :null => false
    end

#Models
  class Band < ActiveRecord::Base
    has_and_belongs_to_many :members, :class_name => 'User'
  end

  class User < ActiveRecord::Base
    has_and_belongs_to_many :bands
  end

由此我现在可以调用 @band.members 或 @user.bands

I do a similar thing on a site I'm working on but the associations are a little different to how you're doing it but maybe it'll help. I think you need to use the has_and_belongs_to_many association to join up your many-to-many's.

In my database I have Users, Members and UsersMembers

You don't need to create a UsersMembers model (GroupMembership in your case) but you do need a database table to link the two.

#Migration
    create_table :bands_users, :id => false, :force => true do |t|
      t.integer :band_id,       :null => false
      t.integer :user_id,       :null => false
    end

#Models
  class Band < ActiveRecord::Base
    has_and_belongs_to_many :members, :class_name => 'User'
  end

  class User < ActiveRecord::Base
    has_and_belongs_to_many :bands
  end

From this I can now call @band.members or @user.bands

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