通过 Node.Js 进行 mongoDB 连接的 MongoNetworkError

Question

I'm new to Node.Js and learning through tutorials, I have already installed the mongoDB server and mongoDB compass. Trying to run it with Visual Studio code and windows powershell - but I couldn't connect app to mongoDB.

code:

const mongoose = require('mongoose'); 
mongoose.connect('mongodb://localhost/playground').then(()=>
console.log('connected to mongodb..'))
.catch(err => console.error('could not connect to MongoDB..', err));

Error:

could not connect to MongoDB.. MongoNetworkError: failed to connect to server [localhost:27017] on first connect [Error: connect ECONNREFUSED 127.0.0.1:27017
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1128:14) {
  name: 'MongoNetworkError',
  message: 'connect ECONNREFUSED 127.0.0.1:27017',
  stack: 'Error: connect ECONNREFUSED 127.0.0.1:27017\n' +
    '    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1128:14)'
}]

Any help is much appreciated.

Answer 1

Looks like you're missing the port number. An example of connection string would be mongodb://localhost:27017/MyDb

Answer 2

I don't know Node.js or MongoDB.

However, the error message looks common to me. It seems that localhost refuses the connection on port 27017. So the first thing I would check is if the DB server really is listening on that port.

I even don't know whether your stack runs under Windows or under Linux. But both of them have a tool called netstat which you can use to check who is listening on port 27017. If nobody listens there, you know that your DB server did not start as intended.

Another reason for the malfunction could be a firewall which blocks inbound connections to port 27017. This is unlikely in your case, though, because the connection to be established is from localhost to localhost ; such connections usually are not blocked by firewalls.

Answer 3

If you are using Windows and install mongoDB to C drive then you should create two
directory in C drive one is "data" and inside data create "db" like C://data/db

open your cmd panel and type mongod -dbpath c://data/db and your mongodb service is running and now you able to connect mongoDB

Answer 4

If you're new in the field too, you gonna have setup problems with some PORTS ...

The easy way: just use MongoDB ATLAS (2 minutes setup)

The first tutorial I found on google: https://developerhandbook.com/mongodb/connect-mongo-atlas-mongoose/