Question

我有两个模型：ActivityFeed (:id, :activity_id,...)和ActivityTour (:activity_id, :tour_id)。

class ActivityFeed < ApplicationRecord
    has_many :activity_tours, foreign_key: :activity_id
end

class ActivityTour < ApplicationRecord
    belongs_to :activity_feed, foreign_key: :activity_id
end

我创建了两条记录，例如：a = ActivityFeed.create(activity_id: 123,..)和b = ActivityTour.create(activity_id: 123,..)。

我预计b.activity_feed会返回a，但会返回nil。

这是查询SELECT "activity_feeds".* FROM "activity_feeds" WHERE "activity_feeds"."id" = $1 LIMIT $2 [["id", 123], ["LIMIT", 1]]。

请告诉我需要解决的问题。我将非常感激

Answer 1

请尝试创建如下关联：

class ActivityFeed < ApplicationRecord
  has_many :activity_tours, foreign_key: :activity_id, primary_key: :activity_id
end

class ActivityTour < ApplicationRecord
  belongs_to :activity_feed, foreign_key: :activity_id, primary_key: :activity_id
end

Answer 2

当您将activity_id设置为ActivityFeed时，活动记录区分ActivityTour和foreign_key是不明确的。因此，将ActivityTour结构更改为ActivityTour (:activity_feed_id, :tour_id)是合适的。然后将关联定义为：

   class ActivityFeed < ApplicationRecord
      has_many :activity_tours, foreign_key: :activity_feed_id
   end

   class ActivityTour < ApplicationRecord
      belongs_to :activity_feed, foreign_key: :activity_feed_id
   end

Rails：如何在关联上设置自定义键

2 个答案: