我收集了两个mongodb，* * 流程和用户**及以下我有它们的示例文档。我尝试查询流程文档，但将嵌套在事件对象中的用户ID替换为用户名而不是用户ID。如果我在"历史"对象中可能有多个嵌套对象，最好的方法是什么？（在节点上运行并使用本机驱动程序，而不是使用mongoose）。

• • 工艺文件**

{
    _id: ObjectId('63d96b68e7b92dceb334f4cb'),
    status: 'active',
    history: {
        {
            type: 'created',
            userID: '61e77cdedde2dbe1cbf8a250',
            date: 'Tue Jan 31 2023 17:31:32 GMT+0000 (Coordinated Universal Time)'
        },
        {
            type: 'updated',
            userID: 'd6xMtHTIX3QO0FifUPgoJLOLz872',
            date: 'Tue Jan 31 2023 18:31:32 GMT+0000 (Coordinated Universal Time)'
        },
        {
            type: 'updated',
            userID: '61e77cdedde2dbe1cbf8a250',
            date: 'Tue Jan 31 2023 19:31:32 GMT+0000 (Coordinated Universal Time)'
        },

    }
}

• • 用户1文档**

{
    _id: ObjectId('d6xMtHTIX3QO0FifUPgoJLOLz872'),
    email: 'something@something.com',
    firstname: 'Bobby',
    lastname: 'Tables',
}

• • 用户2文档**

{
    _id: ObjectId('61e77cdedde2dbe1cbf8a250'),
    email: 'something2@something.com',
    firstname: 'Jenny',
    lastname: 'Tables',
}

• • 我要找的实际产量**

{
    _id: ObjectId('63d96b68e7b92dceb334f4cb'),
    status: 'active',
    history: {
        {
            type: 'created',
            userName: 'Jenny Tables',
            date: 'Tue Jan 31 2023 17:31:32 GMT+0000 (Coordinated Universal Time)'
        },
        {
            type: 'updated',
            userName: 'Bobby Tables',
            date: 'Tue Jan 31 2023 18:31:32 GMT+0000 (Coordinated Universal Time)'
        },
        {
            type: 'updated',
            userName: 'Jenny Tables',
            date: 'Tue Jan 31 2023 19:31:32 GMT+0000 (Coordinated Universal Time)'
        },

    }
}

• • 下面是我尝试过的方法**，我可以生成现有数据并更新一条记录的名称，但不是所有记录：

try {
    const db = mongo.getDB();
    const data = db.collection("processes");
    data.aggregate([
        {$sort: {_id: -1}}, 
        {$lookup: {from: 'users', localField: 'history.userID', foreignField: '_id', as: 'User'}},
        {$unwind: '$User'},
        {$addFields: {"history.userName": { '$concat': ['$User.firstname', ' ', '$User.lastname']}}},
        {$project:{_id: 1, status: 1, history: 1}}
    ]).toArray(function(err, result) {
        if (err)
            res.status(500).send('Database array error.');
        console.log(result);
        res.status(200).send(result);
    });

} catch (err) {
    console.log(err);
    res.status(500).send('Database error.');
}

• • 编辑：**

前一个答案很可能是正确的，我得到的错误是由于在用户集合上使用uid而不是_id（我相信）：
下面是我的尝试：

data.aggregate([
    {$unwind: "$history"},
    {"$lookup": {from: "users", localField: "history.userID", foreignField: "uid", as: "userLookup"}},
    {$unwind: "$userLookup"},
    {$project: {status: 1, history: {type: "$history.type", userName: {"$concat": ["$userLookup.firstname"," ","$userLookup.lastname"]}, date: "$history.date"}}},
    {$group: {_id: "$_id",status: {$first: "$status"}, history: {push: "$history"}}},
    {"$merge": {into: "process", on: "_id",whenMatched: "merge"}}
]).toArray(function(err, result) {
    console.log(result);
    if (err)
    {
        res.status(500).send('Database array error.');
        console.log(err);
    }
    else
        res.status(200).send(result);
});

用户文档（现在）：

{
    _id: ObjectId('d6xMtHTIX3QO0FifUPgoJLOLz872'),
    uid: 'werwevmA5gZ2Ky2MUuSAj6TJiZz1',
    email: 'something@something.com',
    firstname: 'Bobby',
    lastname: 'Tables',
}