Run:
make
Check out the google group http://groups.google.com/group/node-mongodb-native for questions/answers from users of the driver.
This is a node.js driver for MongoDB. It's a port (or close to a port) of the libary 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, {})),
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.a === 2);
// Let's close the db
client.close();
});
});
};
client.open(function(err, p_client) {
client.collection('test_insert', test);
});
To enable the driver to use the C/C++ bson parser pass it the option native_parser:true like below
var client = new Db('integration_tests_20',
new Server("127.0.0.1", 27017),
{native_parser:true});
The version V0.8.0 > contains a C/C++ native BSON parser, this leads to some small changes in the way you need to access the BSON classes as you need to use the right versions of the classes with the right driver.
To access the correct version of BSON objects for your instance do the following
client.bson_serializer.Long
client.bson_serializer.ObjectID
client.bson_serializer.Timestamp
client.bson_serializer.DBRef
client.bson_serializer.Binary
client.bson_serializer.Code
The source code is available at http://github.com/christkv/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.
For examples look in the examples/ directory. You can execute the examples using node.
$ cd examples $ node queries.js
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
For more information about how to connect to a replicaset have a look at Replicasets
The current version does not support connection pooling, but it will be implemented soon.
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();
});
});
});
});
});
});
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();
});
});
});
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.
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 object from the database. The convenience methods
each
and toArray
call nextObject
until the cursor is exhausted.
Signatures:
collection.find(query, [fields], options);
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 options of find
:
limit
andskip
numbers used to control paging.sort
an array of sort preferences like this:[['field1','asc'], ['field2','desc']]
. As a shorthand, ascending fields can be written as simply the field name instead of['field','asc']
. Furthermore, if you are sorting by a single ascending field, you can smply enter the field name as a string without the surrounding array.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);
});
});
Signature:
collection.insert(docs, options, [callback]);
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, {}).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. (fine for collecting some statistics,
bad for most use cases (see "MongoDB is Web Scale")).
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 be given an error.
See the MongoDB docs for
the modifier ($inc
, etc.) formats.
Signature:
collection.update(criteria, objNew, options, [callback]);
Useful options:
safe:true
Should always set if you have a callback.multi:true
If set, all matching documents are updated, not just the first.upsert:true
Atomically inserts the document if no documents matched.
Example for update
:
var mongodb = require('mongodb');
var server = new mongodb.Server("127.0.0.1", 27017, {});
new mongodb.Db('test', server, {}).open(function (error, client) {
if (error) throw error;
var collection = new mongodb.Collection(client, 'test_collection');
collection.update({hi: 'here'}, {$set: {hi: 'there'}}, {safe:true},
function(err) {
if (err) console.warn(err.message);
else console.log('successfully updated');
});
});
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.
- The callback does not get an error when the item doesn't exist, just
an
undefined
object.
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, {}).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.
});
});
TODO
The save
method is a shorthand for upsert if the document contains an
_id
, or an insert if there is no _id
.
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 [email protected] 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.
See HISTORY
Copyright 2009 - 2010 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.