Can't connect to mongoDB with node.js using mongoose

Question

This is the code which I've written:

const mongoose = require('mongoose')
const userSchema = require('./userSchema.js')
const User = mongoose.model('user', userSchema, 'user')

async function createUser(username) {
    return new User({
        username,
        created: Date.now()
    }).save()
}

async function findUser(username) {
    return await User.findOne({
        username
    })
}

;
(async() => {
    const connector = mongoose.connect(connectionString)
    const username = process.argv[2].split('=')[1]

    let user = await connector.then(async() => {
        return findUser(username)
    }).catch(console.log("Error found"))

    if (!user) {
        user = await createUser(username)
    }

    console.log(user)
    process.exit(0)
})()

But the following error is coming. i couldn't figure out what is going wrong. Any idea?

code error snippet here

Answer 1

Try this command

sudo service mongod start

Then nodemon or node app.js to start server.

Answer 2

Please check your connection string. You can obtain the connection string from Mongo atlas.

1. https://developerhandbook.com/mongodb/connect-mongo-atlas-mongoose/

Answer 3

const express = require('express');
const bodyParser = require('body-parser');
const mongoose = require('mongoose');
const app = express();


// Connecting to the database
mongoose.connect('mongodb:uri',{ useNewUrlParser: true } ).then(() => {
    console.log("Successfully connected to the database");
}).catch(err => {
    console.log('Could not connect to the database. Exiting now...');
    process.exit();
});