Mysql 通过另一个外键关联外键

我有这3种型号

class User < ActiveRecord::Base
  has_many :answers, :as => :owner
end

class Answer < ActiveRecord::Base
  belongs_to :owner, :polymorphic => true
  has_one :test  
end

class Test < ActiveRecord::Base
  belongs_to :answer
end

但它不起作用，我犯了这个错误

ActiveRecord::HasManyThroughAssociationPolymorphicSourceError: Cannot have a has_many :through association 'Test#owner' on the polymorphic object 'Owner#owner'.

有什么帮助吗？

在

测试中：

delegate :owner, :to => :answer

您必须指定
source\u type
选项，因为
owner
是多态关联

class Test < ActiveRecord::Base
  belongs_to :answer
  has_one :owner, :through => :answer, :source_type => "User"
end

类测试：答案，：源类型=>“用户”
结束
您是否尝试过
has_one:user，：through=>：answer
？是的，它不起作用，如果它起作用，我想与owner打交道，因为我有许多模型充当：owner
class Test < ActiveRecord::Base
  belongs_to :answer
  has_one :owner, :through => :answer, :source_type => "User"
end