javascript - Mongodb mongoose - 如果字段不存在，如何将文档添加到数组

Question

这样的文档

{
    "_id" : ObjectId("5db65eb2a2f3a61fe88e162a"), 
    "devicesCxt" : [
        {
            "deviceId" : "1232", 
            "userAgent" : "PostmanRuntime/7.19.0", 
            "online" : false, 
            "_id" : ObjectId("5db65eb2a2f3a61fe88e162c"), 
            "loginAt" : ISODate("2019-10-28T03:21:22.178+0000")
        }
    ], 
}

我要添加这个

{
    "deviceId" : "1233", 
    "userAgent" : "PostmanRuntime/7.19.0", 
    "online" : false, 
    "_id" : ObjectId("5db65eb2a2f3a61fe88e162b"), 
    "loginAt" : ISODate("2019-10-28T03:21:22.178+0000")
}

我想要这样的东西

{
    "_id" : ObjectId("5db65eb2a2f3a61fe88e162a"), 
    "devicesCxt" : [
        {
            "deviceId" : "1232", 
            "userAgent" : "PostmanRuntime/7.19.0", 
            "online" : false, 
            "_id" : ObjectId("5db65eb2a2f3a61fe88e162c"), 
            "loginAt" : ISODate("2019-10-28T03:21:22.178+0000")
        },
        {
            "deviceId" : "1233", 
            "userAgent" : "PostmanRuntime/7.19.0", 
            "online" : false, 
            "_id" : ObjectId("5db65eb2a2f3a61fe88e162b"), 
            "loginAt" : ISODate("2019-10-28T03:21:22.178+0000")
        }
    ],
}

如果 deviceId: 1232 不允许，否则 deviceId: 1233 可以成功。

deviceId 不能有相同的对象

deviceId 应该在数组中保持唯一。

我该怎么做？

Answer 1

当 deviceId 为传入对象已经存在。 $push

Mongo 查询:

const incomingDoc = {
  deviceId: "1233",
  userAgent: "PostmanRuntime/7.19.0",
  online: false,
  _id: ObjectId("5db65eb2a2f3a61fe88e162b"),
  loginAt: ISODate("2019-10-28T03:21:22.178+0000")
};

db.collection.update(
  {
    _id: idToFilterIfAny,
    "devicesCxt.deviceId": { $ne: incomingDoc.deviceId }
  },
  { $push: { devicesCxt: incomingDoc } }
);