Question

这应该很容易。我想我一定会被命名。

“经理”和“下属”（员工）都属于“人”类。

这就是我所拥有的：

class Person < ActiveRecord::Base
  has_many :person_manager_assignments
  has_many :managers, :through => :person_manager_assignments
  has_many :subordinates, :through => :person_manager_assignments
end

class PersonManagerAssignment < ActiveRecord::Base
  has_one :subordinate, :class_name => "Person", :foreign_key => "id", :primary_key => 'person_id'
  has_one :manager, :class_name => "Person", :foreign_key => "id", :primary_key => 'manager_id'
end

这对于检查和分配经理非常有用。

关于下属，我抓住了这个问题。它返回人的自我，而不是他们的下属：

p.subordinates
  Person Load (0.5ms)  SELECT "people".* FROM "people" INNER JOIN "person_manager_assignments" ON "people"."id" = "person_manager_assignments"."person_id" WHERE "person_manager_assignments"."person_id" = 15973

请参阅WHERE子句中与“person_id”匹配的位？我需要它是“manager_id”，但是弄乱PersonManagerAssignment关联foreign_key和primary_key值似乎没有帮助。

有什么想法吗？

Answer 1

答案基本上就在这里：http://railscasts.com/episodes/163-self-referential-association

所以我认为你需要这个：

class Person < ActiveRecord::Base
  has_many :person_manager_assignments
  has_many :managers, :through => :person_manager_assignments
  has_many :subordinate_relationships, :class_name=>"PersonManagerAssignment", :foreign_key=>"manager_id"
  has_many :subordinates, :through => :subordinate_relationships, :source=>:person
end

和

class PersonManagerAssignment < ActiveRecord::Base
  belongs_to :person
  belongs_to :manager, :class_name=>"Person"
end

摇滚。

Answer 2

我猜你的PersonManagerAssignment表中有一个person_id和一个manager_id以及模型中的关联，如has_one：person和has_one：manager。如果是这种情况，我建议更改此关联

has_one :person

到这个

has_one :subordinate, :class_name => "Person", :foreign_key => "person_id"

然后你的has_many：下属应该按预期工作。

Answer 3

class Person < ActiveRecord::Base
  has_many :subordinates :through => :person_manager_assignments
  has_many :managers,    :through => :person_manager_assignments
end

class PersonManagerAssignment < ActiveRecord::Base
  belongs_to :subordinate, :class_name => 'Person'
  belongs_to :manager,     :class_name => 'Person'
end

ActionRecord建模：拥有众多经理的员工

3 个答案: