Question

我有以下型号：

class UserShareTag < ActiveRecord::Base
  attr_protected :sharee_id, :post_id, :sharer_id

  belongs_to :sharer, :class_name => "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，我有以下一行：

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。

有些相关问题 - 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"

如何合并其他逻辑：user_shared_posts应包含以下内容：sharer_id是user_id？并且：recommended_posts应包含以下内容：sharee_id是user_id？

提前致谢！

Answer 1

您只需要向:source个关联添加has_many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

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

1 个答案: