ActiveRecord的有两个协会 [英] ActiveRecord has two association

问题描述

什么是实现有两个协会的ActiveRecord的最佳方法是什么？

我有一个团队和游戏模式。每个小组将have_many游戏 @ team.games 。博弈将有两支队伍 @ game.hosting_team 和 @ game.opposing_team 。

我开始了两个 belongs_to的/ HAS_ONE 的关联，但随后 @ team.games 只会返回他们的主场比赛

其他的选择，我能想到的是使用HABTM和使用验证，以确保只有记录。唯一缺少的是跟踪主队。好像我需要一个有许多通过关联，但我不是很确定...

感谢您的帮助。

这是两个has_many关联如何看一个例子。这里的问题是我必须调用 team.games 和 team.opponents 来得到他们的游戏的完整列表

 类团队及LT;的ActiveRecord :: Base的
  的has_many：游戏
  的has_many：对手：将class_name =＆GT; 团队＃：foreign_key =＆GT; 
结束

一流的游戏和LT;的ActiveRecord :: Base的
  belongs_to的：团队：将class_name =＆GT; 团队＃：foreign_key =＆GT; TEAM_ID
  belongs_to的：对手：将class_name =＆GT; 团队＃：foreign_key =＆GT; opponent_id
结束
 

我想这样的事情，但是这显然并不怎么belongs_to的工作。

 类团队及LT;的ActiveRecord :: Base的
  的has_many：游戏
结束

一流的游戏和LT;的ActiveRecord :: Base的
  belongs_to的：hosting_team
  belongs_to的：opposing_team
结束
 

我需要的API应该是这样的。

  @ team.games＃返回所有的游戏在家或外出
@ game.hosting_team＃团队
@ game.opposing_team＃团队
 

解决方案

您可以或许仍与BT /豪关联建模它，并设置了游戏，对球队的存取方法，而不是作为一个协会：

 类团队及LT;的ActiveRecord :: Base的
  高清游戏
    Game.find（：条件=＆GT;home_team_id = OR away_team_id =？，ID，ID]）
  结束
结束
 

What is the best way to achieve a has two association with activerecord?

I have a Team and Game models. Each Team will have_many games @team.games. A Game will have two teams @game.hosting_team and @game.opposing_team.

I started out with two belongs_to/has_one associations but then @team.games would only return their home games.

The other option I can think of is using a HABTM and use a validator to ensure there are only records. The only thing missing is keeping track of the home team. It seems like I need a has many through association but I'm not exactly sure...

Thanks for your help.

This is an example of how the two has_many associations look. The problem here is I would have to call team.games and team.opponents to get a full list of their games

class Team < ActiveRecord::Base
  has_many :games
  has_many :opponents, :class_name => "Team"#, :foreign_key => ""
end

class Game < ActiveRecord::Base
  belongs_to :team, :class_name => "Team" #, :foreign_key => "team_id"
  belongs_to :opponent, :class_name => "Team" #, :foreign_key => "opponent_id"
end

I'd like something like this but this obviously isn't how belongs_to works.

class Team < ActiveRecord::Base
  has_many :games
end

class Game < ActiveRecord::Base
  belongs_to :hosting_team
  belongs_to :opposing_team
end

My desired api would look like this.

@team.games # return all games home or away
@game.hosting_team # Team
@game.opposing_team # Team

解决方案

You can probably still model it with the bt/ho associations, and set up games as an accessor method on the team instead of as an association:

class Team < ActiveRecord::Base
  def games
    Game.find(:conditions => ["home_team_id = ? OR away_team_id = ?", id, id])
  end
end

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