如何接收连接表中根据条件的对象 [英] how to receive objects by condition in connecting table

问题描述

我有表游戏和徽章他们连接由表 BadgesGames 。

I have table Games and Badges they are connecting by table BadgesGames.

t.integer "badge_id"
t.integer "game_id"
t.boolean "shown",    default: false

我有游戏对象，我想找到所有徽章这wans't 显示

I have Game object and i want find all Badges which wans't shown

game_object.(condition?).badges

如何获得的呢？

How to get it?

推荐答案

假设你有一个 has_​​and_belongs_to_many '到'关系成立：

Assuming you have a has_and_belongs_to_many 'through' relationship set up:

class Game < ActiveRecord::Base
  has_many :game_badges
  has_many :badges, through: :game_badges
end

class GameBadge < ActiveRecord::Base
  belongs_to :game
  belongs_to :badge
end

class Badge < ActiveRecord::Base
  has_many :game_badges
  has_many :games, through: :game_badges
end

然后你可以用下面的：

Then you can use the following:

game.game_badges.where(shown: false).map(&:badge)

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