用户销毁时的Rails多态关联错误

Question

I'm trying to link notifications to users like so.

  belongs_to :notified_by, class_name: 'User'

My user has_many notifications.

  has_many :notifications, dependent: :delete_all

The problem is, when I try to destroy a user, I get an error when it goes to delete all the notifications.

ActiveRecord::StatementInvalid (PG::UndefinedColumn: ERROR:  column notifications.user_id does not exist)
LINE 1: DELETE FROM "notifications" WHERE "notifications"."user_id" ...

There is no user_id in the Notifications table, just a notified_by_id. I have tried using that in place of notified_by, but that didn't work either.

Answer 1

我必须在用户模型中设置外键，以将notify_by_id识别为要查找的列。

  has_many :notifications, foreign_key: 'notified_by_id', dependent: :delete_all