CODEWITHSUNDEEP
node.jsmongodbmongoosesocket.io
ProgrammingNoob
ProgrammingNoob

Reputation: 17

TypeError: Cannot read property 'on' of undefined in node js and mongoose

I am getting an error when i run my application.

The error: 

 MongoDB.on('error', function(err) { console.log(err.message); });
 TypeError: Cannot read property 'on' of undefined
 ...

I tried to comment that part of the code out to see if i have anymore similar errors and found another same one. ( This time the word "once" )

The code: 

var mongoURI = "mongodb://localhost/chatapp";
var MongoDB = mongoose.connect(mongoURI).connection;
MongoDB.on('error', function(err) { console.log(err.message); });
MongoDB.once('open', function() {
    console.log("mongodb connection open");
});

It would be really great if anyone could help me solve this :( I searched the internet and found nothing helpful.

Upvotes: 0

Views: 4368

Answers (4)

oarkon
oarkon

Reputation: 1

const config = require('../config');
const Mongoose = require('mongoose');

Mongoose.connect(config.dbURI);
Mongoose.connection.once('open',()=>{
    console.log('Connected to db');
});

it helps me.

Upvotes: 0

SAGAR RAVAL
SAGAR RAVAL

Reputation: 319

var mongoose = require('mongoose');
var mongoURI = "mongodb://localhost/chatapp";
var MongoDB = mongoose.connect(mongoURI).connection;
MongoDB.on('error', function(err) { console.log(err.message); });
MongoDB.once('open', function() {
    console.log("mongodb connection open");
});

also before running the application in your terminal type npm install mongoose --save

Upvotes: 1

Diogo Aleixo
Diogo Aleixo

Reputation: 871

The message is pretty clear. MongoDb is undefined.

Speaking on your MongoDb variable. Should be mongoDb with lowercase. It is one instance.

Anyway, the problem is in mongoose.connect(mongoURI).connection. Debug from there.

Upvotes: 0

Aayush Jaiswal
Aayush Jaiswal

Reputation: 11

Try this:

   const mongoose = require('mongoose');

    mongoose.connect(mongoURI);
    mongoose.connection.once('open',()=>{
        console.log('Connected to db');
    });

Upvotes: 0

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