Up to date documentation
Install
To install the most recent release from npm, run:
npm install mongodb
That may give you a warning telling you that bugs['web'] should be bugs['url'], it would be safe to ignore it (this has been fixed in the development version)
To install the latest from the repository, run::
npm install path/to/node-mongodb-native
Community
Check out the google group node-mongodb-native for questions/answers from users of the driver.
Try it live
Introduction
This is a node.js driver for MongoDB. It's a port (or close to a port) of the library for ruby at http://github.com/mongodb/mongo-ruby-driver/.
A simple example of inserting a document.
var client = new Db('test', new Server("127.0.0.1", 27017, {}), {w: 1}),
test = function (err, collection) {
collection.insert({a:2}, function(err, docs) {
collection.count(function(err, count) {
test.assertEquals(1, count);
});
// Locate all the entries using find
collection.find().toArray(function(err, results) {
test.assertEquals(1, results.length);
test.assertTrue(results[0].a === 2);
// Let's close the db
client.close();
});
});
};
client.open(function(err, p_client) {
client.collection('test_insert', test);
});
Data types
To store and retrieve the non-JSON MongoDb primitives (ObjectID, Long, Binary, Timestamp, DBRef, Code).
In particular, every document has a unique _id
which can be almost any type, and by default a 12-byte ObjectID is created. ObjectIDs can be represented as 24-digit hexadecimal strings, but you must convert the string back into an ObjectID before you can use it in the database. For example:
// Get the objectID type
var ObjectID = require('mongodb').ObjectID;
var idString = '4e4e1638c85e808431000003';
collection.findOne({_id: new ObjectID(idString)}, console.log) // ok
collection.findOne({_id: idString}, console.log) // wrong! callback gets undefined
Here are the constructors the non-Javascript BSON primitive types:
// Fetch the library
var mongo = require('mongodb');
// Create new instances of BSON types
new mongo.Long(numberString)
new mongo.ObjectID(hexString)
new mongo.Timestamp() // the actual unique number is generated on insert.
new mongo.DBRef(collectionName, id, dbName)
new mongo.Binary(buffer) // takes a string or Buffer
new mongo.Code(code, [context])
new mongo.Symbol(string)
new mongo.MinKey()
new mongo.MaxKey()
new mongo.Double(number) // Force double storage
The C/C++ bson parser/serializer
If you are running a version of this library has the C/C++ parser compiled, to enable the driver to use the C/C++ bson parser pass it the option native_parser:true like below
// using native_parser:
var client = new Db('integration_tests_20',
new Server("127.0.0.1", 27017),
{native_parser:true});
The C++ parser uses the js objects both for serialization and deserialization.
GitHub information
The source code is available at http://github.com/mongodb/node-mongodb-native. You can either clone the repository or download a tarball of the latest release.
Once you have the source you can test the driver by running
$ make test
in the main directory. You will need to have a mongo instance running on localhost for the integration tests to pass.
Examples
For examples look in the examples/ directory. You can execute the examples using node.
$ cd examples
$ node queries.js
GridStore
The GridStore class allows for storage of binary files in mongoDB using the mongoDB defined files and chunks collection definition.
For more information have a look at Gridstore
Replicasets
For more information about how to connect to a replicaset have a look at Replicasets
Primary Key Factories
Defining your own primary key factory allows you to generate your own series of id's (this could f.ex be to use something like ISBN numbers). The generated the id needs to be a 12 byte long "string".
Simple example below
// Custom factory (need to provide a 12 byte array);
CustomPKFactory = function() {}
CustomPKFactory.prototype = new Object();
CustomPKFactory.createPk = function() {
return new ObjectID("aaaaaaaaaaaa");
}
var p_client = new Db('integration_tests_20', new Server("127.0.0.1", 27017, {}), {'pk':CustomPKFactory});
p_client.open(function(err, p_client) {
p_client.dropDatabase(function(err, done) {
p_client.createCollection('test_custom_key', function(err, collection) {
collection.insert({'a':1}, function(err, docs) {
collection.find({'_id':new ObjectID("aaaaaaaaaaaa")}, function(err, cursor) {
cursor.toArray(function(err, items) {
test.assertEquals(1, items.length);
// Let's close the db
p_client.close();
});
});
});
});
});
});
Strict mode
Each database has an optional strict mode. If it is set then asking for a collection that does not exist will return an Error object in the callback. Similarly if you attempt to create a collection that already exists. Strict is provided for convenience.
var error_client = new Db('integration_tests_', new Server("127.0.0.1", 27017, {auto_reconnect: false}), {strict:true});
test.assertEquals(true, error_client.strict);
error_client.open(function(err, error_client) {
error_client.collection('does-not-exist', function(err, collection) {
test.assertTrue(err instanceof Error);
test.assertEquals("Collection does-not-exist does not exist. Currently in strict mode.", err.message);
});
error_client.createCollection('test_strict_access_collection', function(err, collection) {
error_client.collection('test_strict_access_collection', function(err, collection) {
test.assertTrue(collection instanceof Collection);
// Let's close the db
error_client.close();
});
});
});
Documentation
If this document doesn't answer your questions, see the source of Collection or Cursor, or the documentation at MongoDB for query and update formats.
Find
The find method is actually a factory method to create
Cursor objects. A Cursor lazily uses the connection the first time
you call nextObject
, each
, or toArray
.
The basic operation on a cursor is the nextObject
method
that fetches the next matching document from the database. The convenience
methods each
and toArray
call nextObject
until the cursor is exhausted.
Signatures:
var cursor = collection.find(query, [fields], options);
cursor.sort(fields).limit(n).skip(m).
cursor.nextObject(function(err, doc) {});
cursor.each(function(err, doc) {});
cursor.toArray(function(err, docs) {});
cursor.rewind() // reset the cursor to its initial state.
Useful chainable methods of cursor. These can optionally be options of find
instead of method calls:
.limit(n).skip(m)
to control paging..sort(fields)
Order by the given fields. There are several equivalent syntaxes:.sort({field1: -1, field2: 1})
descending by field1, then ascending by field2..sort([['field1', 'desc'], ['field2', 'asc']])
same as above.sort([['field1', 'desc'], 'field2'])
same as above.sort('field1')
ascending by field1
Other options of find
:
fields
the fields to fetch (to avoid transferring the entire document)tailable
if true, makes the cursor tailable.batchSize
The number of the subset of results to request the database to return for every request. This should initially be greater than 1 otherwise the database will automatically close the cursor. The batch size can be set to 1 withbatchSize(n, function(err){})
after performing the initial query to the database.hint
See Optimization: hint.explain
turns this into an explain query. You can also callexplain()
on any cursor to fetch the explanation.snapshot
prevents documents that are updated while the query is active from being returned multiple times. See more details about query snapshots.timeout
if false, asks MongoDb not to time out this cursor after an inactivity period.
For information on how to create queries, see the MongoDB section on querying.
var mongodb = require('mongodb');
var server = new mongodb.Server("127.0.0.1", 27017, {});
new mongodb.Db('test', server, {}).open(function (error, client) {
if (error) throw error;
var collection = new mongodb.Collection(client, 'test_collection');
collection.find({}, {limit:10}).toArray(function(err, docs) {
console.dir(docs);
});
});
Insert
Signature:
collection.insert(docs, options, [callback]);
where docs
can be a single document or an array of documents.
Useful options:
safe:true
Should always set if you have a callback.
See also: MongoDB docs for insert.
var mongodb = require('mongodb');
var server = new mongodb.Server("127.0.0.1", 27017, {});
new mongodb.Db('test', server, {w: 1}).open(function (error, client) {
if (error) throw error;
var collection = new mongodb.Collection(client, 'test_collection');
collection.insert({hello: 'world'}, {safe:true},
function(err, objects) {
if (err) console.warn(err.message);
if (err && err.message.indexOf('E11000 ') !== -1) {
// this _id was already inserted in the database
}
});
});
Note that there's no reason to pass a callback to the insert or update commands
unless you use the safe:true
option. If you don't specify safe:true
, then
your callback will be called immediately.
Update; update and insert (upsert)
The update operation will update the first document that matches your query
(or all documents that match if you use multi:true
).
If safe:true
, upsert
is not set, and no documents match, your callback will return 0 documents updated.
See the MongoDB docs for
the modifier ($inc
, $set
, $push
, etc.) formats.
Signature:
collection.update(criteria, objNew, options, [callback]);
Useful options:
safe:true
Should always set if you have a callback.multi:true
If set, all matching documents are updated, not just the first.upsert:true
Atomically inserts the document if no documents matched.
Example for update
:
var mongodb = require('mongodb');
var server = new mongodb.Server("127.0.0.1", 27017, {});
new mongodb.Db('test', server, {w: 1}).open(function (error, client) {
if (error) throw error;
var collection = new mongodb.Collection(client, 'test_collection');
collection.update({hi: 'here'}, {$set: {hi: 'there'}}, {safe:true},
function(err) {
if (err) console.warn(err.message);
else console.log('successfully updated');
});
});
Find and modify
findAndModify
is like update
, but it also gives the updated document to
your callback. But there are a few key differences between findAndModify and
update:
- The signatures differ.
- You can only findAndModify a single item, not multiple items.
Signature:
collection.findAndModify(query, sort, update, options, callback)
The sort parameter is used to specify which object to operate on, if more than one document matches. It takes the same format as the cursor sort (see Connection.find above).
See the MongoDB docs for findAndModify for more details.
Useful options:
remove:true
set to a true to remove the object before returningnew:true
set to true if you want to return the modified object rather than the original. Ignored for remove.upsert:true
Atomically inserts the document if no documents matched.
Example for findAndModify
:
var mongodb = require('mongodb');
var server = new mongodb.Server("127.0.0.1", 27017, {});
new mongodb.Db('test', server, {w: 1}).open(function (error, client) {
if (error) throw error;
var collection = new mongodb.Collection(client, 'test_collection');
collection.findAndModify({hello: 'world'}, [['_id','asc']], {$set: {hi: 'there'}}, {},
function(err, object) {
if (err) console.warn(err.message);
else console.dir(object); // undefined if no matching object exists.
});
});
Save
The save
method is a shorthand for upsert if the document contains an
_id
, or an insert if there is no _id
.
Sponsors
Just as Felix Geisendörfer I'm also working on the driver for my own startup and this driver is a big project that also benefits other companies who are using MongoDB.
If your company could benefit from a even better-engineered node.js mongodb driver I would appreciate any type of sponsorship you may be able to provide. All the sponsors will get a lifetime display in this readme, priority support and help on problems and votes on the roadmap decisions for the driver. If you are interested contact me on christkv AT g m a i l.com for details.
And I'm very thankful for code contributions. If you are interested in working on features please contact me so we can discuss API design and testing.
Release Notes
See HISTORY
Credits
Contributors
Aaron Heckmann, Christoph Pojer, Pau Ramon Revilla, Nathan White, Emmerman, Seth LaForge, Boris Filipov, Stefan Schärmeli, Tedde Lundgren, renctan, Sergey Ukustov, Ciaran Jessup, kuno, srimonti, Erik Abele, Pratik Daga, Slobodan Utvic, Kristina Chodorow, Yonathan Randolph, Brian Noguchi, Sam Epstein, James Harrison Fisher, Vladimir Dronnikov, Ben Hockey, Henrik Johansson, Simon Weare, Alex Gorbatchev, Shimon Doodkin, Kyle Mueller, Eran Hammer-Lahav, Marcin Ciszak, François de Metz, Vinay Pulim, nstielau, Adam Wiggins, entrinzikyl, Jeremy Selier, Ian Millington, Public Keating, andrewjstone, Christopher Stott, Corey Jewett, brettkiefer, Rob Holland, Senmiao Liu, heroic, gitfy
License
Copyright 2009 - 2012 Christian Amor Kvalheim.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.