ruby-on-rails - 创建一个 has_many 关联，其中条件适用于 ruby​​ on rails 中的主表？

Question

我authentications有很多用作primary_key和groupsforeign_key ，没问题。uidorganizer_id

但uid在属性范围内是唯一的provider。我想确保我的关联只获取groupswhere authentication.provider == 'meetup'。我试过了：

has_many :groups, :primary_key => "uid", :foreign_key => "organizer_id", :conditions => {:provider => "meetup"}

但这只是试图找到groups所有provider == "meetup"

如何在主表上指定条件authentications？

Answer 1

尝试：

has_many :groups, :primary_key => "uid", :foreign_key => "organizer_id", :include => :authentication, :conditions => {:authentication => {:provider => "meetup"}}

更新：

如果 Group belongs_to身份验证使用“organizer_id”作为 foreign_key，那么只需：

Group.includes(:authentication).where(:authentication => {:provider => "meetup"})