MongoDB获取子文档

本文介绍了MongoDB获取子文档的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我想从MongoDB中的文档中检索子文档.我有以下文件:

I would like to retrieve a sub document from a document in MongoDB. I have the following document:

{ "_id" : "10000", "password" : "password1", "name" : "customer1", "enabled" : true, "channels" : [ { "id" : "10000-1", "name" : "cust1chan1", "enabled" : true }, { "id" : "10000-2", "name" : "cust1chan2", "enabled" : true } ] }

我想要的结果是:

{ "id" : "10000-1", "name" : "cust1chan1", "enabled" : true }

但是，到目前为止，我能做的最好的就是使用以下查询:

However, the best I can do so far is using the following query:

db.customer.find({"channels.id" : "10000-1"}, {"channels.$" : 1, "_id" : 0})

但这给了我以下结果:

{ "channels" : [ { "id" : "10000-1", "name" : "cust1chan1", "enabled" : true } ] }

有人知道是否可以编写一个查询给我我想要的结果吗?任何帮助将不胜感激.

Does anyone know if it is possible to write a query that will give me my desired result? Any help would be much appreciated.

推荐答案

您可以使用Aggregation Framework做到这一点.查询将类似于:

You can do it with Aggregation Framework. Query will be something like :

db.customer.aggregate([ {$unwind : "$channels"}, {$match : {"channels.id" : "10000-1"}}, {$project : {_id : 0, id : "$channels.id", name : "$channels.name", enabled : "$channels.enabled"}} ])