MongoDB美元($)前缀字段' $ unset'在' $ unset'对存储错误无效

时间:2016-04-29 10:21:45

标签: node.js mongodb mongodb-query

我正在尝试使用MongoDB的Node.js驱动程序更新文档

我正在执行两个操作,一个修改字段的值,另一个删除字段,我正在使用的代码如下:

db.collection("myCollection").updateOne({_id: "testDocument"}, {val1:"newval",$unset:{val2:""}}, function(err, result){
//Code that logs the error

因此记录了错误并产生错误代码52和以下堆栈跟踪:

MongoError: The dollar ($) prefixed field '$unset' in '$unset' is not valid for storage.
    at Function.MongoError.create (/home/ubuntu/workspace/node_modules/mongodb/node_modules/mongodb-core/lib/error.js:31:11)
    at toError (/home/ubuntu/workspace/node_modules/mongodb/lib/utils.js:114:22)
    at /home/ubuntu/workspace/node_modules/mongodb/lib/collection.js:1008:67
    at commandCallback (/home/ubuntu/workspace/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:1161:9)
    at Callbacks.emit (/home/ubuntu/workspace/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:119:3)
    at messageHandler (/home/ubuntu/workspace/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:295:23)
    at Socket.dataHandler (/home/ubuntu/workspace/node_modules/mongodb/node_modules/mongodb-core/lib/connection/connection.js:285:22)
    at emitOne (events.js:77:13)
    at Socket.emit (events.js:169:7)
    at readableAddChunk (_stream_readable.js:146:16)

我做错了什么?我确信在执行命令时文档中存在两个字段,那么如何修复此错误? (是的,它肯定连接到服务器)

1 个答案:

答案 0 :(得分:2)

如果要修改字段值,则需要使用$set运算符。

db.collection("myCollection").updateOne({ "_id": "testDocument" },
    { 
        "$set": { "val1": "newval" }, 
        "$unset" : { "val2": "" } 
    }, function(err, result){
        // dosomething()
})