MongoDB查询比较没有$ where的同一集合中的2个字段 [英] MongoDB query comparing 2 fields in same collection without $where

问题描述

MongoDB是否支持使用本地运算符(而不是$ where和JavaScript)比较同一集合中的两个字段? 我已经看过相似

Does MongoDB supports comparing two fields in same collection by using native operators (not $where and JavaScript)? I already looked at similar questions and all answers used $where / JavaScript.

MongoDB 文档明确指出:

MongoDB documentation clearly states that:

JavaScript的执行速度比本页上列出的本机运算符慢，但是非常灵活.

JavaScript executes more slowly than the native operators listed on this page, but is very flexible.

我主要关心的是速度，如果可能的话，我想使用索引.那么在不使用JavaScript的情况下可以比较MongoDB中的两个字段吗?

My primary concern is speed and I would like to use indexes if possible. So is comparing two fields in MongoDB possible without using JavaScript?

推荐答案

当前无法实现，但是通过当前正在开发的新聚合框架(2.1+)可以实现.该聚合框架是本机框架，不依赖于相对较慢的JavaScript执行路径.

This is not currently possible, but it will be possible through the new aggregation framework currently under development (2.1+). This aggregation framework is native and does not rely on relatively slow JavaScript execution paths.

有关更多详细信息，请检查 http://www.mongodb.org/display/DOCS/Aggregation+Framework 以及 https://jira.mongodb.org/browse/SERVER-447

For more details check http://www.mongodb.org/display/DOCS/Aggregation+Framework and the progress at https://jira.mongodb.org/browse/SERVER-447

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