“复杂”ActiveRecord 关联

Question

在设置一些 Active Record 关系时遇到了一些问题。

Users Leagues

Users 有很多PrimaryLeagues Users有很多SecondaryLeagues

我希望能够编写@user.primary_leagues 并获得已设置为主要的Leagues 列表。和@user.secondary_leagues 并获取已设置为辅助的Leagues 列表。

目前这里是我的课程的设置方式，但不知何故它是错误的......

class User < ActiveRecord::Base

has_many :primary_leagues, class_name: 'PrimaryLeague', foreign_key: 'league_id'

has_many :secondary_leagues, class_name: 'SecondaryLeague', foreign_key: 'league_id'

...

class PrimaryLeague < ActiveRecord::Base

belongs_to :user
belongs_to :league

...

class League < ActiveRecord::Base

has_many :primary_users, class_name: 'PrimaryLeague', foreign_key: 'user_id'
has_many :secondary_users, class_name: 'SecondaryLeague', foreign_key: 'user_id'

有什么想法吗？

Answer 1

据我了解，您只想对整个事情使用两个类（这是有道理的）。所以：

class User < ActiveRecord::Base
  has_many        :primary_league_ownerships
  has_many        :primary_leagues,
                  :through => :primary_league_ownerships,
                  :source => :league
  has_many        :secondary_league_ownerships
  has_many        :secondary_leagues,
                  :through => :secondary_league_ownerships,
                  :source => :league
end

class PrimaryLeagueOwnership < ActiveRecord::Base
  belongs_to      :user
  belongs_to      :league
end

class SecondaryLeagueOwnership < ActiveRecord::Base
  belongs_to      :user
  belongs_to      :league
end

class League < ActiveRecord::Base
  has_many        :primary_league_ownerships
  has_many        :primary_users,
                  :through => :primary_league_ownerships,
                  :source => :user
  has_many        :secondary_league_ownerships
  has_many        :secondary_users,
                  :through => :secondary_league_ownerships,
                  :source => :user
end

请记住，:class_name 应该是保存目标关联的实际类。