Ruby on rails Rails ActiveRecord:：AssociationTypeMismatch

我正在尝试创建

通知

以添加

用户朋友

。 但是，当我尝试向错误中添加朋友时

友谊模式

class Friendship < ApplicationRecord
  after_save :notification

  belongs_to :user
  belongs_to :friend, class_name: "User"
  has_many :notification

  private
  def all_friendships
    @all_friend = Friendship.order('created_at DESC').limit(1)
  end

  def notification
    all_friendships.each do |friend|
      Notification.create(recipient: friend.friend_id, actor: self.user, action: "add friend", notifiable: friend)
    end
  end
end

class Notification < ApplicationRecord
  belongs_to :recipient, class_name: "User"
  belongs_to :actor, class_name: "User"
  belongs_to :notifiable, polymorphic: true

  scope :unread, -> { where(read_at: nil) }
end

---

您可以设置

朋友id

（整数），而不是用户模型（收件人：friend.frien\u id）。需要设置用户模型。尝试：

def notification
    all_friendships.each do |friend|
      Notification.create(recipient: friend, actor: self.user, action: "add friend", notifiable: friend)
    end
  end

更新：调用

友谊

类

朋友

的变量是不好的，因为

朋友

应该是

用户

。 无论如何，代码如下：

def notification
    all_friendships.each do |friend|
      Notification.create(recipient: friend.friend, actor: self.user, action: "add friend", notifiable: friend)
    end
end

---

无论如何，一个错误用户（#70140183755940）更新了响应

def notification
    all_friendships.each do |friend|
      Notification.create(recipient: friend, actor: self.user, action: "add friend", notifiable: friend)
    end
  end

def notification
    all_friendships.each do |friend|
      Notification.create(recipient: friend.friend, actor: self.user, action: "add friend", notifiable: friend)
    end
end