当我尝试使用post方法将mongoDB与nodejs express连接时，我只是添加了一个记录器，如果nodejs侦听mongoDB，则会显示消息数据库已连接，但我发现尽管post方法正在工作，但Mongoclient不工作，因此记录器不工作，首先，我尝试使用(MongoClient.connect("mongodb://localhost:27017)，但它导致在控制台中显示(MongooseServerSelectionError: connect ECONNREFUSED ::1:27017)，所以我用(MongoClient.connect('mongodb://127.0.0.1:27017')替换了localhost。现在的结果是简单地用表单输入记录控制台，但应用程序仍然不听mongoDB，请帮助我，我完全是一个初学者
这里是代码

var express = require('express');
var router = express.Router();
var MongoClient=require("mongodb").MongoClient
/* GET home page. */
router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' });
});
router.post('/',function(req,res,next){
  console.log(req.body);
  next
})
router.post("/submit",function(req,res) {
  console.log(req.body);

  MongoClient.connect('mongodb://127.0.0.1:27017',function(err,client){
    if(err)
      console.log('error')
    
    else
    console.log('database connected');
     client.db('bynode').collection("users").insertOne(req.body)
  })
  res.send("got it")
  
})

module.exports = router;

请帮助我，我坚持与我的学习，因为这个错误
/error/F:\new space\node_modules\mongodb\lib\sdam\topology.js:278 const timeoutError = new error_1.MongoServerSelectionError(服务器选择在${serverSelectionTimeoutMS} ms后超时，this.description）; ^ MongoServerSelectionError: connect ECONNREFUSED ::1:27017 at Timeout._onTimeout (F:\new space\node_modules\mongodb\lib\sdam\topology.js:278:38) at listOnTimeout (node:internal/timers:569:17) at process.processTimers (node:internal/timers:512:7) { reason: TopologyDescription { type: 'Unknown', servers: Map(1) { 'localhost:27017' => ServerDescription { address: 'localhost:27017', type: 'Unknown', hosts: [], passives: [], arbiters: [], tags: {}, minWireVersion: 0, maxWireVersion: 0, roundTripTime: -1, lastUpdateTime: 24984871, lastWriteDate: 0, error: MongoNetworkError: connect ECONNREFUSED ::1:27017 at connectionFailureError (F:\new space\node_modules\mongodb\lib\cmap\connect.js:379:20) at Socket. (F:\new space\node_modules\mongodb\lib\cmap\connect.js:285:22) at Object.onceWrapper (node:events:629:26) at Socket.emit (node:events:514:28) at emitErrorNT (node:internal/streams/destroy:151:8) at emitErrorCloseNT (node:internal/streams/destroy:116:3) at process.processTicksAndRejections (node:internal/process/task_queues:82:21) { [Symbol(errorLabels)]: Set(1) { 'ResetPool' }, [cause]: Error: connect ECONNREFUSED ::1:27017 at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1495:16) { errno: -4078, code: 'ECONNREFUSED', syscall: 'connect', address: '::1', port: 27017 } }, topologyVersion: null, setName: null, setVersion: null, electionId: null, logicalSessionTimeoutMinutes: null, primary: null, me: null, '$clusterTime': null } }, stale: false, compatible: true, heartbeatFrequencyMS: 10000, localThresholdMS: 15, setName: null, maxElectionId: null, maxSetVersion: null, commonWireVersion: 0, logicalSessionTimeoutMinutes: null }, code: undefined, [Symbol(errorLabels)]: Set(0) {}, [cause]: MongoNetworkError: connect ECONNREFUSED ::1:27017 at connectionFailureError (F:\new space\node_modules\mongodb\lib\cmap\connect.js:379:20) at Socket. (F:\new space\node_modules\mongodb\lib\cmap\connect.js:285:22) at Object.onceWrapper (node:events:629:26) at Socket.emit (node:events:514:28) at emitErrorNT (node:internal/streams/destroy:151:8) at emitErrorCloseNT (node:internal/streams/destroy:116:3) at process.processTicksAndRejections (node:internal/process/task_queues:82:21) { [Symbol(errorLabels)]: Set(1) { 'ResetPool' }, [cause]: Error: connect ECONNREFUSED ::1:27017 at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1495:16) { errno: -4078, code: 'ECONNREFUSED', syscall: 'connect', address: '::1', port: 27017 } } }
我尝试将MongoClient.connect("mongodb://localhost:27017更改为MongoClient.connect('mongodb://127.0.0.1:27017，不同的是(MongooseServerSelectionError: connect ECONNREFUSED ::1:27017)的错误消息消失了，但节点仍然没有监听mongoDB，我希望记录器会显示“数据库已连接”，并且表单输入将存储到bynode中的数据库中，因为收集用户。