Question

User有许多订阅者和许多发布者，两者都是用户：

class User < ActiveRecord::Base
    has_many :relationships, :foreign_key => "subscriber_id"
    has_many :subscribers, :through => :relationships, :source => :subscriber

    has_many :inverse_relationships, :class_name => "Relationship", :foreign_key => "publisher_id"
    has_many :publishers, :through => :inverse_relationships, :source => :publisher

    def subscribe_to(publisher)
        self.relationships.create!(publisher_id: publisher.id, subscriber_id: id)
    end
end

class Relationship < ActiveRecord::Base
    belongs_to :subscriber, :class_name => "User"
    belongs_to :publisher, :class_name => "User"
end

用户订阅的用户的发布者。

但是，如果我执行john.subscribe_to(a_publisher)，然后尝试puts john.publishers，我会返回一个空数组。

我来回地随意改变外键和来源，希望它最终会起作用，但有些东西是关闭的。源和外键应该在这里？

更新

以下是我的工作：

class User < ActiveRecord::Base
    has_many :relationships, :foreign_key => "publisher_id"
    has_many :subscribers, :through => :relationships, :source => :subscriber

    has_many :inverse_relationships, :foreign_key => "subscriber_id", :class_name => "Relationship"
    has_many :publishers, :through => :inverse_relationships, :source => :publisher

    def subscribe_to(publisher)
        publisher.relationships.create!(subscriber_id: id)
    end
end

首先，我为两者切换了外键。第二，这是我不理解的部分，我改变了

self.relationships.create!(publisher_id: publisher.id)

到

publisher.relationships.create!(subscriber_id: id)

它有效。出于某种原因，它没有相反的工作方式。任何人都可以解释原因吗？

Answer 1

您的协会似乎很奇怪。你应该这样试试：

 has_many :subscribers, :through => :relationships, :class_name => 'User'

并致电：

 john.subscribers.create(a_publisher)

您所说的subscriber只是User。我认为你的问题来自这里。

也许您可以尝试：:source => :user

Rails has_many through，外键和源代码问题

更新

1 个答案: