MongoDB：尝试根据嵌套子文档中匹配条件的数量更新字段

问题描述

我有下面的嵌套文档数组，并尝试更新“ readCounter”（即数字）。我想将“ readCounter”设置为匹配条件的文档数：“ userId”：“ naveen”和“ otherUserIds.otherUserId”：“ ashwini”和“ messages.sentBy”：“ ashwini”。在以下情况下，上述条件的readCounter应该设置为“ 2”。请帮助我进行MongoDB查询以更新“ readCounter”。

我使用下面的查询进行更新，但结果不正确。

AllChats.aggregate(
    [
        {
            $match: {
                userId: details.userId,"otherUserIds.otherUserId": details.otherUserId,"messages.sentBy": details.otherUserId
            }
        },{
                $set: { $count: "otherUserIds.$.msgReadCounter"}
            }
    ]
);

下面是数据库数据：

AllChats = [{
        "_id" : ObjectId("5f43fb76167f53d3d46b52ef"),"userId" : "naveen","otherUserIds" : [
                {
                        "otherUserId" : "ashwini","readCounter" : 0,"messages" : [
                                {
                                        "msg" : "Hi Naveen","sentBy" : "ashwini"
                                },{
                                        "msg" : "Hi Ashwini","sentBy" : "naveen"
                                },{
                                        "msg" : "How are you today",{
                                        "msg" : "I'm good","sentBy" : "naveen"
                                }
                        ]
                },{
                        "otherUserId" : "testuser","messages" : [
                                {
                                        "msg" : "Hi naveen","sentBy" : "testuser"
                                },{
                                        "msg" : "Im good",{
                                        "msg" : "how are you today",{
                                        "msg" : "how are you testuser","sentBy" : "naveen"
                                }
                        ]
                }
        ]
}
{
        "_id" : ObjectId("5f440e5e167f53d3d46b52f0"),"userId" : "ashwini","otherUserIds" : [
                {
                        "otherUserId" : "naveen","message" : [
                                {
                                        "msg" : "Hi Naveen","sentBy" : "naveen"
                                }
                        ]
                }
        ]
}]

解决方法

我自己找到了解决方案，但价格昂贵。它涉及两个单独的数据库查询，因此我愿意接受更好的解决方案。

try{
        let counter = await AllChats.aggregate([
            {$match: {userId: details.userId}},{$unwind: "$otherUserIds"},{$match: {"otherUserIds.otherUserId": details.otherUserId}},{$unwind: "$otherUserIds.messages"},{$match: {"otherUserIds.messages.sentBy": details.otherUserId}},{$count: "counter"}
        ]);

        console.log(counter[0]);
        if(counter[0] !== undefined){
        await AllChats.findOneAndUpdate(
            {userId: details.userId},{$set: {"otherUserIds.$[elem].msgReadCounter": counter[0].counter}},{arrayFilters: [{"elem.otherUserId": details.otherUserId}]}
            );
            console.log("Updated message read counter");
        }
    } catch(err){

        console.log(err);
}