如何在连接表中按条件接收对象

我有桌子Games and Badges他们通过桌子连接BadgesGames.

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

I have Game对象，我想找到所有Badges这不是shown

game_object.(condition?).badges

如何获得？

假设你有一个has_and_belongs_to_many建立“通过”关系：

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

然后您可以使用以下内容：

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