查询中对MongoDB $的响应顺序? [英] Order of responses to MongoDB $in query?

问题描述

$ in 条件运算符不对顺序说任何话.如果我运行以下形式的查询

The MongoDB docs on the $in conditional operator don't say anything about order. If I run a query of the form

db.things.find({'_id': {'$in': id_array}});

返回结果的顺序是什么?

what will be the order of the returned results? And is there a way for me to tell MongoDB "I want the results sorted so that they're in the same order as the ids in id_array?"

推荐答案

在很快得到了很好的答复:使用$or代替$in

Quickly got a pretty good response: use $or instead of $in

c.find( { _id:{ $in:[ 1, 2, 0 ] } } ).toArray()

vs.

c.find( { $or:[ { _id:1 }, { _id:2 }, { _id:0 } ] } ).toArray()

阅读错误报告以获取更多信息.

Read the bug report for more info.

更新:

$ or解决方法从2.6.x开始不再起作用-这是实现的副作用，它具有

The $or work-around hack no longer works starting with 2.6.x - it was a side effect of implementation which has changed.

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