demo.js

var mongoose = require("mongoose")
dbInit = ()=>{
	mongoose.connect('mongodb://localhost/dataviz');
	var db = mongoose.connection;
	db.on('error', console.error.bind(console, 'connection error:'));
	db.once('open', function() {
	  // we're connected!
		console.log("We are connected!");

		// var mongoose = require('mongoose');
		var user = mongoose.Schema({
		    name: String,
		    emailId: String,
		    password: String
		});
		var User = mongoose.model('user', user);
		var user = new User({name: 'asd'});
		var user1 = new User({name: 'asdasd', emailId: 'pop@pop.com'});
		user.save(function (err, user) {
		    if (err) return console.error(err);
			console.log(user, 'asd');
			user1.save(function (err, user) {
			    if (err) return console.error(err);
				console.log(user, 'asd');
				user1.save(function (err, user) {
				    if (err) return console.error(err);
					console.log(user, 'asd');

				});
			});
		});

		User.find({name: 'asd'}, function (err, users) {
		  if (err) return console.error(err);
		  console.log(users);
		});


		User.update({emailId: 'pop@pop.com'}, {password: 'adaf'}, function(err, done){
			if(err) throw err;
			console.log(done)	;
		})


		User.deleteMany({name: 'asd'}, (err, done) => {
			if (err) return console.error(err);
		  	console.log(done);
		});
		
		


	});
}

dbInit();