I've been trying to make a simple site with Node.js, Express.js, and MongoDB. I'm new to these technologies and have been having problem set up the database Here is snippet of code in my index.js file:

var http = require('http'),
    express = require('express'),
    path = require('path'),
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    CollectionDriver = require('./collectionDriver').CollectionDriver;

var app = express();
app.set('port', process.env.PORT || 3000);
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

var mongoHost = 'localHost';
var mongoPort = 27017;
var collectionDriver;

var mongoClient = new MongoClient(new Server(mongoHost, mongoPort));
mongoClient.open(function(err, mongoClient) {
  if (!mongoClient) {
      console.error("Error! Exiting... Must start MongoDB first");
      process.exit(1);
  }
  var db = mongoClient.db("MyDatabase");
  collectionDriver = new CollectionDriver(db);
});

After I try to run node index.js in terminal, it says the following:

js-bson: Failed to load c++ bson extension, using pure JS version

/Users/username/dev/ga-final/index.js:31
mongoClient.open(function(err, mongoClient) { //C
            ^
TypeError: Object #<MongoClient> has no method 'open'
at Object.<anonymous> (/Users/username/dev/ga-final/index.js:31:13)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Function.Module.runMain (module.js:497:10)
at startup (node.js:119:16)
at node.js:906:3

What is wrong? Why can't I call open? Can you help me fix this? thanks!

I've been trying to make a simple site with Node.js, Express.js, and MongoDB. I'm new to these technologies and have been having problem set up the database Here is snippet of code in my index.js file:

var http = require('http'),
    express = require('express'),
    path = require('path'),
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    CollectionDriver = require('./collectionDriver').CollectionDriver;

var app = express();
app.set('port', process.env.PORT || 3000);
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

var mongoHost = 'localHost';
var mongoPort = 27017;
var collectionDriver;

var mongoClient = new MongoClient(new Server(mongoHost, mongoPort));
mongoClient.open(function(err, mongoClient) {
  if (!mongoClient) {
      console.error("Error! Exiting... Must start MongoDB first");
      process.exit(1);
  }
  var db = mongoClient.db("MyDatabase");
  collectionDriver = new CollectionDriver(db);
});

After I try to run node index.js in terminal, it says the following:

js-bson: Failed to load c++ bson extension, using pure JS version

/Users/username/dev/ga-final/index.js:31
mongoClient.open(function(err, mongoClient) { //C
            ^
TypeError: Object #<MongoClient> has no method 'open'
at Object.<anonymous> (/Users/username/dev/ga-final/index.js:31:13)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Function.Module.runMain (module.js:497:10)
at startup (node.js:119:16)
at node.js:906:3

What is wrong? Why can't I call open? Can you help me fix this? thanks!

• javascript
• node.js
• mongodb
• express
• database

• ping check my answer :) – squiroid Commented Mar 29, 2015 at 10:55

2 Answers 2

This is happening may be because you are using new version of mongodb it is working fine after I use mongodb driver version 1.4.

npm install [email protected]

Take a look at the mongodb docs. Your mongoClient object is not what you think it is, and that why there isn't an open() method available.

Make your example code look more like theirs:

var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');

// Connection URL
var url = 'mongodb://localhost:27017/myproject';
// Use connect method to connect to the Server
MongoClient.connect(url, function(err, db) {
  assert.equal(null, err);
  console.log("Connected correctly to server");

  db.close();
});