ruby on rails has_many：通过关联，其中有两列具有相同的模型

我有以下型号：

class UserShareTag  "User" belongs_to :post belongs_to :sharee, :class_name => "User" validates :sharer_id, :presence => true validates :sharee_id, :presence => true validates :post_id, :presence => true end 

在Post模型中，我有以下几行：

 has_many :user_share_tags, :dependent => :destroy has_many :user_sharers, :through => :user_share_tags, :uniq => true, :class_name => "User" has_many :user_sharees, :through => :user_share_tags, :uniq => true, :class_name => "User" 

我如何表达：user_sharers应该对应于：sharer_id？ 和：user_sharees应该对应于：sharee_id？ 由于它们都是相同的用户模型，我不确定该怎么做。

一些相关的问题 – 在用户模型中我有：

 has_many :user_share_tags, :dependent => :destroy has_many :user_shared_posts, :through => :user_share_tags, :uniq => true, :class_name => "Post" has_many :recommended_posts, :through => :user_share_tags, :uniq => true, :class_name => "Post" 

如何合并以下附加逻辑：user_shared_posts应包含以下内容：sharer_id是user_id？ 并且：recommended_posts应该包含以下内容：sharee_id是user_id？

提前致谢！

Answer 1

您只需要在has_many关联中添加:source参数（并且您不需要:class_name选项）：

 has_many :user_sharers, :through => :user_share_tags, :source => :sharer, :uniq => true, :class_name => "User" has_many :user_sharers, :through => :user_share_tags, :source => :sharee, :uniq => true, :class_name => "User" 

然后在您的User模型中，您需要一个额外的has_many关联：

 has_many :user_share_tags_as_sharee, :class_name => "UserShareTag", :foreign_key => :sharee_id, :dependent => :destroy has_many :user_share_tags_as_sharer, :class_name => "UserShareTag", :foreign_key => :sharer_id, :dependent => :destroy has_many :user_shared_posts, :source => :post, :through => :user_share_tags_as_sharer, :uniq => true has_many :recommended_posts, :source => :post, :through => :user_share_tags_as_sharee, :uniq => true