rails :dependent=>:destroy 被忽略

Question

我的关联选项似乎没有兑现。

class ClassRoom < ActiveRecord::Base
  has_many :class_assignments, :dependent => :destroy
  has_many :people, :through=>:class_assignments

class Person < ActiveRecord::Base
  has_many :class_assignments, :dependent => :destroy
  has_many :class_rooms, :through=>:class_assignments

class ClassAssignment < ActiveRecord::Base
  belongs_to :person
  belongs_to :class_room

也就是说，当一个人或一个教室被删除时，连接表/模型中的记录也应该被删除。

但是，ClassRoom.last.destroy 破坏了 ClassRoom，但没有任何关联 ClassAssignments。

我知道:dependent=>:destroy 在使用:through 时会被忽略，但我应该可以在连接模型上使用它吧？

Answer 1

试试

  class ClassRoom < ActiveRecord::Base 
  def before_destroy
    self.class_assignments.destroy_all
  end

人也一样