Mongodb native driver and Expressjs intergration

app.js

var express = require('express');
var app = express();
var MongoClient = require('mongodb').MongoClient;

MongoClient.connect('mongodb://127.0.0.1:27017/test', function(err, db) {
  var collection = db.collection('collection');

  app.get('/', function(req, res) {
    collection.find().toArray(function(err, results) {
      res.json(results);
    });
  });

  app.get('/insert', function(req, res) {
    collection.insert({a: 1}, function() {
      res.redirect('/');
    });
  });

  app.listen(3000);
});