3

我有一个用户模型，它可能有很多活动（出于统计目的，我正在跟踪我的用户执行的一些操作）

class User < ActiveRecord::Base
  has_many :activities
  has_many :histories,:through => :activities # ?
end

class Activity < ActiveRecord::Base
  belongs_to :user
  belongs_to :history, :polymorphic => true
end

class BrowsingHistory < ActiveRecord::Base
  has_many :activities,:as => :histories
end

class LoginHistory < ActiveRecord::Base
  has_many :activities,:as => :histories
end

...

该类Activity有 a history_type:string、 ahistory_id:integer和 a user_id:integer，我希望它能够容纳BrowsingHistory或LoginHistory对象。

我在多态关联方面的工作很少，从我到目前为止的情况来看，我一直收到错误：ActiveRecord::HasManyThroughAssociationPolymorphicSourceError:Cannot have a has_many :through association 'User#histories' on the polymorphic object 'History#history'. 我阅读了有关该主题的一些相关问题，但我无法找到解决方案。

编辑：我想我明白了（控制台测试似乎有效），你能确认一下吗？

class User < ActiveRecord::Base
  has_many :activities
  has_many :login_histories,:through => :activities,:source => :history,:source_type => "LoginHistory"
end

class Activity < ActiveRecord::Base
  belongs_to :user
  belongs_to :history, :polymorphic => true
end

class BrowsingHistory < ActiveRecord::Base
  has_many :activities,:as => :history
  has_many :users,:through => :activities
end

class LoginHistory < ActiveRecord::Base
  has_many :activities,:as => :history
  has_many :users,:through => :activities
end
4

1 回答 1

3

这很好用：

class User < ActiveRecord::Base
  has_many :activities
  has_many :login_histories,:through => :activities,:source => :history,:source_type => "LoginHistory"
end

class Activity < ActiveRecord::Base
  belongs_to :user
  belongs_to :history, :polymorphic => true
end

class BrowsingHistory < ActiveRecord::Base
  has_many :activities,:as => :history
  has_many :users,:through => :activities
end

class LoginHistory < ActiveRecord::Base
  has_many :activities,:as => :history
  has_many :users,:through => :activities
end
于 2012-08-30T21:11:39.457 回答