Rails has_many通過似乎不起作用

Question

我需要第二眼。 當我在兩個玩家之間創建比賽時，Tournament.players返回一個空數組。

碼

class Tournament < ActiveRecord::Base
  has_many :player_matches
  has_many :matches
  has_many :players, :through => :player_matches  
end

class PlayerMatch < ActiveRecord::Base
  belongs_to :player
  belongs_to :match
  belongs_to :tournament
end

class Player < ActiveRecord::Base
  has_many :player_matches
  has_many :matches, :through => :player_matches
  has_many :tournaments, :through => :player_matches
end

Answer 1

您需要具有double :through關系：

player_matches通過matches和players通過player_matches 。

class Tournament < ActiveRecord::Base
  has_many :matches
  has_many :player_matches, :through => :matches
  has_many :players, :through => :player_matches  
end

class PlayerMatch < ActiveRecord::Base
  belongs_to :player
  belongs_to :match
end

class Player < ActiveRecord::Base
  has_many :player_matches
  has_many :matches, :through => :player_matches
  has_many :tournaments, :through => :player_matches
end

class Match < ActiveRecord::Base
  belongs_to :tournament  
  has_many :player_matches
  has_many :players, :through => :player_matches
end