两个相似的多对多关系

Question

我有两个相似的 M:M 关系，我单独处理它们，但我不知道如何在不冲突的情况下处理它们。

关系是球员和球队

1) Many players "play for" many teams

2) Many players "are members of" many teams

class Player < ActiveRecord::Base
  has_many :plays
  has_many :members
  has_many :teams, through: :plays
  has_many :teams, through: :members
end

class Teams < ActiveRecord::Base
  has_many :plays
  has_many :members
  has_many :players, through: :plays
  has_many :players, through: :members
end

class Play < ActiveRecord::Base
  belongs_to :players
  belongs_to :teams
end

class Member < ActiveRecord::Base
  belongs_to :players
  belongs_to :teams
end

我需要能够找到：

Player.find(21).teams #who he plays for
Player.find(21).teams #who he is a member of

Answer 1

您必须为每个 has_many 协会指定不同的名称，并使用 source 参数指定实际的协会名称。

像这样：

class Player < ActiveRecord::Base
  has_many :plays
  has_many :memberships
  has_many :played_with_teams, through: :plays, source: :team
  has_many :member_of_teams, through: :memberships, source: :team
end

class Team < ActiveRecord::Base
  has_many :plays
  has_many :memberships
  has_many :played_players, through: :plays, source: :player
  has_many :member_players, through: :members, source: :player
end

class Play < ActiveRecord::Base
  belongs_to :player
  belongs_to :team
end

class Membership < ActiveRecord::Base
  belongs_to :player
  belongs_to :team
end

可以这样使用：

Player.find(21).played_with_teams #who he plays for
Player.find(21).member_of_teams #who he is a member of

提示：我更新了答案。

两个相似的多对多关系

Two similar Many-to-Many Relationships

ruby-on-rails

activerecord

many-to-many

associations

has-many-through