[루비 온 레일] Rails Association-다중 모델 능력

Newsletter Model
  has_many :subscriptions
    has_many :subscribers, through: :subscriptions, source: :user 
      belongs_to :creator, class_name: "User", foreign_key: "user_id"
      
       Subscription Model
         # fields: user_id, newsletter_id
           belongs_to :newsletter
             belongs_to :user
             
              User Model
                # fields: id
                  has_many :subscriptions
                    has_many :subscribed_newsletters, through: :subscriptions, source: :newsletter
                      has_many :created_newsletters, class_name: "Newsletter", foreign_key: "user_id"
                      

이제 구독자와 제작자를 얻을 수 있습니다.

newsletter.subscribers
newsletter.creator

출처
https://stackoverflow.com/questions/22050366