ruby-on-rails - 排序多态关联的最佳方法

Question

所以 - 具有以下设置:

class Event < ActiveRecord::Base
 has_many :invitations
end

class Invitation < ActiveRecord::Base
  belongs_to :guest, :polymorphic => true
  belongs_to :event
end

class Member > ActiveRecord::Base
  has_many :invitations, :as => :guest

  def full_name
    [first_name, last_name].join(" ")
  end
end

class Visitor > ActiveRecord::Base
  has_many :invitations, :as => :guest

  def full_name
    name
  end
end

最后，我希望能够获取由客人全名订购的事件邀请。我不知道如何 - 谁能帮我解决这个问题？将不胜感激:)

Answer 1

至于full_name是一个虚拟属性我能想象只有ruby解决方案，没有sql

event = Event.find some event
event.invitations.sort_by(&:full_name)