Unable to connect to MongoDB using node.js - node.js

Question

I installed MongoDB in my machine and I'm able to start mongod and connect to the db using the mongo command. I even imported some data in the mycol collection of the mydb db:
$ sudo start mongodb
mongodb start/running, process 31008
$ mongo
MongoDB shell version: 2.4.9
connecting to: test
> use mydb
switched to db mydb
> db.mycol.count();
5730
> ^C
bye
But now if I want to access the db via node.js it doesn't work anymore, I get a TypeError.
I try this code (UPDATED):
var MongoClient = require('mongodb').MongoClient;
MongoClient.connect('mongodb://localhost:27017/mydb', function(err, db) {
if(err) throw err;
console.log("connected!");
});
This is based on the npm module mongodb, I also tried mongoose and mongojs, each time with the same result. As soon as I want to connect to the database, I get a TypeError.
$ node mngclient.js
Failed to load c++ bson extension, using pure JS version
events.js:172
throw TypeError('type must be a string');
^
TypeError: type must be a string
at TypeError (<anonymous>)
at EventEmitter.once (events.js:172:11)
at Server.Base._registerHandler (/home/odi/dev/mydb/node_modules/mongodb/lib/mongodb/connection/base.js:387:23)
at null.<anonymous> (/home/odi/dev/mydb/node_modules/mongodb/lib/mongodb/connection/server.js:410:12)
at EventEmitter.emit (events.js:91:17)
at null.<anonymous> (/home/odi/dev/mydb/node_modules/mongodb/lib/mongodb/connection/connection_pool.js:111:15)
at EventEmitter.emit (events.js:97:17)
at Socket.<anonymous> (/home/odi/dev/mydb/node_modules/mongodb/lib/mongodb/connection/connection.js:297:10)
at Socket.EventEmitter.emit (events.js:116:20)
at Object.afterConnect [as oncomplete] (net.js:848:10)
UPDATE:
The version of the mongodb npm package is 1.3.23
npm outdated shows no output, so I guess my packages are up-to-date
Using mongoose with the following very simple code brings up the exact same error:
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/mydb');
UPDATE II:
I still couldn't resolve this issue on my machine
I setup the whole project in a virtual machine using vagrant. It works like a charm.

Answer 1

You should read the document , your trying to start a server(I'm not sure why?) here is an example on connecting to the mongo database you already have running :
MongoClient.connect('mongodb://localhost:21017/myDb', function(err, db) {
"use strict";
if(err) throw err;
...//your code
});

Answer 2

Step 1: npm install mongodb
Step 2: create a file, name it suppose : app.js
Paste the following content into the file:
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
// Connection URL
const url = 'mongodb://127.0.0.1:27017';
// Database Name
const dbName = 'myDB';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, client) {
assert.equal(null, err);
console.log("Connected successfully to server");
const db = client.db(dbName);
insertDocuments(db, function() {
client.close();
});
});
const insertDocuments = function(db, callback) {
// Get the documents collection
const collection = db.collection('documents');
// Insert some documents
collection.insertMany([
{a : 1}, {a : 2}, {a : 3}
], function(err, result) {
assert.equal(err, null);
assert.equal(3, result.result.n);
assert.equal(3, result.ops.length);
console.log("Inserted 3 documents into the collection");
callback(result);
});
}
Step 3 : node app.js
Step 4: run mongod and mongo, check updated db list using show dbs
Database will be created and a collection named 'documents' will be added over there.