从数组中删除不起作用 - Mongodb

Question

我有一个如下所示的文档：

email:"y@y.com"
playlist:"name1"
IDs:
  0:"5db87297b96b1405403bcf13"
  1:"5dc88666f5ba4a2901062398"
  2:"5dc88666f5ba4a2901062398"
  3:"5dc88666f5ba4a2901062398"

要从数组中删除的 mongo 查询：

    let removingItem = {$pull:{'IDs':'5db87297b96b1405403bcf13'}}
    collection.updateOne({'email':'y@y.com','playlistName':'name1'},removingItem,function(err,data){
        //res.send({'message':'removed'})
        console.log(data)
        client.close();
    })

我不知道为什么这不起作用。 我也尝试过平等：

let removingItem = {$pull:{'IDs':{$eq:'5db87297b96b1405403bcf13'}}}

对于这两种方法，我在控制台上得到的输出是：

CommandResult {
  result: { n: 1, nModified: 1, ok: 1 },
  connection: Connection {
    _events: [Object: null prototype] {
      error: [Function],
      close: [Function],
      timeout: [Function],
      parseError: [Function],
      message: [Function]
    },
    _eventsCount: 5,
    _maxListeners: undefined,
    id: 0,
    options: {
      host: 'localhost',
      port: 27017,
      size: 5,
      minSize: 0,
      connectionTimeout: 30000,
      socketTimeout: 360000,
      keepAlive: true,
      keepAliveInitialDelay: 300000,
      noDelay: true,
      ssl: false,
      checkServerIdentity: true,
      ca: null,
      crl: null,
      cert: null,
      key: null,
      passphrase: null,
      rejectUnauthorized: false,
      promoteLongs: true,
      promoteValues: true,
      promoteBuffers: false,
      reconnect: true,
      reconnectInterval: 1000,
      reconnectTries: 30,
      domainsEnabled: false,
      legacyCompatMode: true,
      disconnectHandler: [Store],
      cursorFactory: [Function: Cursor],
      emitError: true,
      monitorCommands: false,
      promiseLibrary: [Function: Promise],
      clientInfo: [Object],
      servers: [Array],
      caseTranslate: true,
      dbName: 'test',
      socketTimeoutMS: 360000,
      connectTimeoutMS: 30000,
      retryWrites: true,
      useRecoveryToken: true,
      readPreference: [ReadPreference],
      bson: BSON {}
    },
    logger: Logger { className: 'Connection' },
    bson: BSON {},
    tag: undefined,
    maxBsonMessageSize: 67108864,
    port: 27017,
    host: 'localhost',
    socketTimeout: 360000,
    keepAlive: true,
    keepAliveInitialDelay: 300000,
    connectionTimeout: 30000,
    responseOptions: { promoteLongs: true, promoteValues: true, promoteBuffers: false },
    flushing: false,
    queue: [],
    writeStream: null,
    destroyed: false,
    hashedName: '29bafad3b32b11dc7ce934204952515ea5984b3c',
    workItems: [],
    socket: Socket {
      connecting: false,
      _hadError: false,
      _parent: null,
      _host: 'localhost',
      _readableState: [ReadableState],
      readable: true,
      _events: [Object: null prototype],
      _eventsCount: 5,
      _maxListeners: undefined,
      _writableState: [WritableState],
      writable: true,
      allowHalfOpen: false,
      _sockname: null,
      _pendingData: null,
      _pendingEncoding: '',
      server: null,
      _server: null,
      timeout: 360000,
      [Symbol(asyncId)]: 35,
      [Symbol(kHandle)]: [TCP],
      [Symbol(lastWriteQueueSize)]: 0,
      [Symbol(timeout)]: Timeout {
        _idleTimeout: 360000,
        _idlePrev: [TimersList],
        _idleNext: [TimersList],
        _idleStart: 11117,
        _onTimeout: [Function: bound ],
        _timerArgs: undefined,
        _repeat: null,
        _destroyed: false,
        [Symbol(refed)]: false,
        [Symbol(asyncId)]: 44,
        [Symbol(triggerId)]: 35
      },
      [Symbol(kBytesRead)]: 0,
      [Symbol(kBytesWritten)]: 0
    },
    buffer: null,
    sizeOfMessage: 0,
    bytesRead: 0,
    stubBuffer: null,
    ismaster: {
      ismaster: true,
      maxBsonObjectSize: 16777216,
      maxMessageSizeBytes: 48000000,
      maxWriteBatchSize: 100000,
      localTime: 2019-12-14T19:20:25.165Z,
      logicalSessionTimeoutMinutes: 30,
      minWireVersion: 0,
      maxWireVersion: 7,
      readOnly: false,
      ok: 1
    },
    lastIsMasterMS: 4
  },
  message: BinMsg {
    parsed: true,
    raw: <Buffer 3c 00 00 00 7d 45 00 00 01 00 00 00 dd 07 00 00 00 00 00 00 00 27 00 00 00 10 6e 00 01 00 00 00 10 6e 4d 6f 64 69 66 69 65 64 00 01 00 00 00 01 6f 6b ... 10 more bytes>,
    data: <Buffer 00 00 00 00 00 27 00 00 00 10 6e 00 01 00 00 00 10 6e 4d 6f 64 69 66 69 65 64 00 01 00 00 00 01 6f 6b 00 00 00 00 00 00 00 f0 3f 00>,
    bson: BSON {},
    opts: { promoteLongs: true, promoteValues: true, promoteBuffers: false },
    length: 60,
    requestId: 17789,
    responseTo: 1,
    opCode: 2013,
    fromCompressed: undefined,
    responseFlags: 0,
    checksumPresent: false,
    moreToCome: false,
    exhaustAllowed: false,
    promoteLongs: true,
    promoteValues: true,
    promoteBuffers: false,
    documents: [ [Object] ],
    index: 44,
    hashedName: '29bafad3b32b11dc7ce934204952515ea5984b3c'
  },
  modifiedCount: 1,
  upsertedId: null,
  upsertedCount: 0,
  matchedCount: 1
}

不幸的是，我无法更改数组的格式，否则我将不得不更改很多依赖于这个简单结构的东西。

预先感谢您的帮助

Answer 1

以下是$pull如何处理您正在使用的数据。 注意IDs字段是一个嵌入文档的数组。 这个例子：

输入文件：

{
        "_id" : 1,
        "ids" : [
                {
                        "0" : "zero"
                },
                {
                        "1" : "one"
                },
                {
                        "2" : "two"
                }
        ]
}

更新查询：

db.test.updateOne( { _id: 1 }, { $pull: { "ids": { "1": "one" } } } )

结果：

{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }

{
        "_id" : 1,
        "ids" : [
                {
                        "0" : "zero"
                },
                {
                        "2" : "two"
                }
        ]
}

---

更新：

使用输入文档：

{ "_id" : 1, "ids" : [ "zero", "one", "two" ] }

并且，更新操作：

db.test.updateOne( { _id: 1 }, { $pull: { ids : "one" } } )

结果将是：

{ "_id" : 1, "ids" : [ "zero", "two" ] }