ruby-on-rails - has_many :through looking for inexistent column

Question

我有这 3 个类:

• 用户:

  class User < ActiveRecord::Base
  end
  

• 用户故事:

  class UserStory < ActiveRecord::Base
    belongs_to :owner, class_name: 'User'
    belongs_to :assigned, class_name: 'User'
    belongs_to :board
  
    has_many :comments
    has_many :watched_stories
    has_many :watchers, through: :watched_stories, source: :user
  

  结束

• 观看的故事:

  class WatchedStory < ActiveRecord::Base
    belongs_to :user
    belongs_to :story, class_name: 'UserStory'
  end
  

当我尝试通过 UserStory#watchers 列出所有观察者时，我看到了这个错误:

PG::UndefinedColumn: ERROR:  column watched_stories.user_story_id does not exist

似乎关系 has_many through 是错误的，但我可以看到错误。我在这里错过了什么？

我的迁移:

class CreateWatchedStories < ActiveRecord::Migration
  def change
    create_table :watched_stories do |t|
      t.references :user, index: true
      t.references :story, index: true, references: :user_story

      t.timestamps
    end
  end
end

Answer 1

如果 WatchedStory 和 UserStory 通过 story_id 连接，你需要指定它，否则 Rails 会假定它是 user_story_id:

class WatchedStory < ActiveRecord::Base
  belongs_to :story, class_name: 'UserStory', foreign_key: :story_id
end

class UserStory < ActiveRecord::Base
  has_many :watched_stories, foreign_key: :story_id
end