Mongoid，如何通过references_one协会（以及随后的协会）ORDER_BY？ [英] Mongoid, how to order_by through a references_one association (and subsequent associations)?

问题描述

简单的模型：

class hat
  embedded_in :owner
  field :color
end

class owner
  embedds_one :hat
  referenced_in :house
  field :name
end

class house
  references_one :owner
  field :number
end

所以，简单地放，我们有关联到业主房屋的集合，车主可以有颜色的帽子。

So simply puts, we have collection of houses that are associated to an owner, and the owner can have a colored hat.

我可以简单地通过它们的数量排序的房子：

I can simply sort the house by their number:

House.all.order_by( [[ :number, :asc ]])

不过，我想是订购房子，由他们主人的名字是什么，我非常希望这样写：

But what I want is ordering the house, by the name of their owner, ideally I would like to write:

House.all.order_by( [[ :'owner.name', :asc ]])

但它不工作...

But it does not work...

和进一步，我想能够通过业主的帽子的颜色

And even further I would like to be able to sort the houses by the color of the owner's hat

House.all.order_by( [[ :'owner.hat.color', :asc ]])

任何想法如何，我可以做到这一点，无需重写一切可能的话：）

Any idea how I can achieve this without rewriting everything if possible :)

感谢

亚历

推荐答案

点符号只为嵌入文档是可能的，但你有2集 - 房屋和业主。
在MongoDB中所有者记录一个你只有场house_id在众议院一个记录你没有所有者模型中的任何连接。
所以，唯一的办法就是获取所有房屋，然后使用可枚举＃排序排序实现集合。

Dot notation is possible only for embedded documents, but you have 2 collections - houses and owners. In one of the Owner records in MongoDB you have only field house_id, in one of the House records you dont have any connection to Owner model. So the only way is to fetch all Houses and then to sort achieved collection using Enumerable#sort.

这篇关于Mongoid，如何通过references_one协会（以及随后的协会）ORDER_BY？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！