Mongodb:查找具有至少一个元素与 ObjectID 不匹配的数组的文档 [英] Mongodb: Find documents with array where at least one element does not match ObjectID

问题描述

我正在为 MongoDB 请求而苦苦挣扎.我有一个 Play 架构，其中包含一组 Move 对象.每个 Move 对象都以 ObjectID 的形式保存对 Player 的引用.关注这个问题 我试着做

I am struggling with a MongoDB request. I have a Play schema that holds an array of Move objects. Each Move object holds a reference to a Player in the form of an ObjectID. Following this question I tried to do

{ 'moves.player': { $elemMatch : { $ne : playerId } } }

其中 playerId 保存 ObjectID.但是我得到了错误

where playerId holds an ObjectID. However I get the error

Error: Can't use $elemMatch with ObjectId

我也尝试了以下

{ 'moves.player.str': { $elemMatch : { $ne : playerId.toString() } } }

但它没有找到合适的文件...有什么想法吗?

but it doesn't find the proper documents... Any ideas?

示例

一些播放记录:

A = {
    "moves": [
        { player: { $oid: "56f32fe2f41638de3b3e4773" } },
        { player: { $oid: "56f32fe2f41638de3b3e4774" } }
    ]
}
B = {
    "moves": [
        { player: { $oid: "56f32fe2f41638de3b3e4773" } }
    ]
}

查询playerId = "56f32fe2f41638de3b3e4773" 应该只返回对象A，因为它是唯一一个拥有至少一个玩家不同于56f32fe2f41638de3b3e4773.

Query for playerId = "56f32fe2f41638de3b3e4773" should only return object A, since it is the only one that has an array of moves where at least one of the players is different from 56f32fe2f41638de3b3e4773.

推荐答案

好的，找到问题所在了...就去做

OK, found out where the problem was... Just do

{ "moves": { $elemMatch: { "player": { $ne : playerId } } } }

效果很好！

这篇关于Mongodb:查找具有至少一个元素与 ObjectID 不匹配的数组的文档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！