mongodb

MongoDB legacy driver emulation layer on top of mongodb-core

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Description

The MongoDB driver is the high level part of the 2.0 or higher MongoDB driver and is meant for end users.

whatwhere
documentationhttp://mongodb.github.io/node-mongodb-native/
api-dochttp://mongodb.github.io/node-mongodb-native/2.0/api/
sourcehttps://github.com/mongodb/node-mongodb-native
mongodbhttp://www.mongodb.org/

Think you’ve found a bug? Want to see a new feature in node-mongodb-native? Please open a case in our issue management tool, JIRA:

Bug reports in JIRA for all driver projects (i.e. NODE, PYTHON, CSHARP, JAVA) and the Core Server (i.e. SERVER) project are public.

  • mailing list: https://groups.google.com/forum/#!forum/node-mongodb-native
  • jira: http://jira.mongodb.org/

http://jira.mongodb.org/browse/NODE

QuickStart

The quick start guide will show you how to setup a simple application using node.js and MongoDB. It scope is only how to set up the driver and perform the simple crud operations. For more in depth coverage we encourage reading the tutorials.

Let's create a directory where our application will live. In our case we will put this under our projects directory.

mkdir myproject
cd myproject

Enter the following command and answer the questions to create the initial structure for your new project

npm init

Next we need to edit the generated package.json file to add the dependency for the MongoDB driver. The package.json file below is just an example and your will look different depending on how you answered the questions after entering npm init

{
  "name": "myproject",
  "version": "1.0.0",
  "description": "My first project",
  "main": "index.js",
  "repository": {
    "type": "git",
    "url": "git://github.com/christkv/myfirstproject.git"
  },
  "dependencies": {
    "mongodb": "~2.0"
  },
  "author": "Christian Kvalheim",
  "license": "Apache 2.0",
  "bugs": {
    "url": "https://github.com/christkv/myfirstproject/issues"
  },
  "homepage": "https://github.com/christkv/myfirstproject"
}

Save the file and return to the shell or command prompt and use NPM to install all the dependencies.

npm install

You should see NPM download a lot of files. Once it's done you'll find all the downloaded packages under the node_modules directory.

Let's boot up a MongoDB server instance. Download the right MongoDB version from MongoDB, open a new shell or command line and ensure the mongod command is in the shell or command line path. Now let's create a database directory (in our case under /data).

mongod --dbpath=/data --port 27017

You should see the mongod process start up and print some status information.

Let's create a new app.js file that we will use to show the basic CRUD operations using the MongoDB driver.

First let's add code to connect to the server and the database myproject.

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(errdb) {
  assert.equal(null, err);
  console.log("Connected correctly to server");
 
  db.close();
});

Given that you booted up the mongod process earlier the application should connect successfully and print Connected correctly to server to the console.

Let's Add some code to show the different CRUD operations available.

Let's create a function that will insert some documents for us.

var insertDocuments = function(dbcallback) {
  // Get the documents collection 
  var collection = db.collection('documents');
  // Insert some documents 
  collection.insert([
    {: 1}, {: 2}, {: 3}
  ], function(errresult) {
    assert.equal(err, null);
    assert.equal(3, result.result.n);
    assert.equal(3, result.ops.length);
    console.log("Inserted 3 documents into the document collection");
    callback(result);
  });
}

The insert command will return a results object that contains several fields that might be useful.

  • result Contains the result document from MongoDB
  • ops Contains the documents inserted with added _id fields
  • connection Contains the connection used to perform the insert

Let's add call the insertDocuments command to the MongoClient.connect method callback.

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(errdb) {
  assert.equal(null, err);
  console.log("Connected correctly to server");
 
  insertDocuments(db, function() {
    db.close();
  });
});

We can now run the update app.js file.

node app.js

You should see the following output after running the app.js file.

Connected correctly to server
Inserted 3 documents into the document collection

Let's look at how to do a simple document update by adding a new field b to the document that has the field a set to 2.

var updateDocument = function(dbcallback) {
  // Get the documents collection 
  var collection = db.collection('documents');
  // Update document where a is 2, set b equal to 1 
  collection.update({ a : 2 }
    , { $set: { b : 1 } }, function(errresult) {
    assert.equal(err, null);
    assert.equal(1, result.result.n);
    console.log("Updated the document with the field a equal to 2");
    callback(result);
  });  
}

The method will update the first document where the field a is equal to 2 by adding a new field b to the document set to 1. Let's update the callback function from MongoClient.connect to include the update method.

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(errdb) {
  assert.equal(null, err);
  console.log("Connected correctly to server");
 
  insertDocuments(db, function() {
    updateDocument(db, function() {
      db.close();
    });
  });
});

Next lets remove the document where the field a equals to 3.

var removeDocument = function(dbcallback) {
  // Get the documents collection 
  var collection = db.collection('documents');
  // Insert some documents 
  collection.remove({ a : 3 }, function(errresult) {
    assert.equal(err, null);
    assert.equal(1, result.result.n);
    console.log("Removed the document with the field a equal to 3");
    callback(result);
  });
}

This will remove the first document where the field a equals to 3. Let's add the method to the MongoClient.connect callback function.

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(errdb) {
  assert.equal(null, err);
  console.log("Connected correctly to server");
 
  insertDocuments(db, function() {
    updateDocument(db, function() {
      removeDocument(db, function() {
        db.close();
      });
    });
  });
});

Finally let's retrieve all the documents using a simple find.

We will finish up the Quickstart CRUD methods by performing a simple query that returns all the documents matching the query.

var findDocuments = function(dbcallback) {
  // Get the documents collection 
  var collection = db.collection('documents');
  // Find some documents 
  collection.find({}).toArray(function(errdocs) {
    assert.equal(err, null);
    assert.equal(2, docs.length);
    console.log("Found the following records");
    console.dir(docs);
    callback(docs);
  });
}

This query will return all the documents in the documents collection. Since we removed a document the total documents returned is 2. Finally let's add the findDocument method to the MongoClient.connect callback.

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(errdb) {
  assert.equal(null, err);
  console.log("Connected correctly to server");
 
  insertDocuments(db, function() {
    updateDocument(db, function() {
      removeDocument(db, function() {
        findDocuments(db, function() {
          db.close();
        });
      });
    });
  });
});

This concludes the QuickStart of connecting and performing some Basic operations using the MongoDB Node.js driver. For more detailed information you can look at the tutorials covering more specific topics of interest.