mongots

A Typescript driver for MongoDB converted from mongojs. It wraps mongodb-core.

Motivation

This is an attempt to produce a good quality node.js driver for MongoDB using the features provided by typescript. Currently, it does everything what mongojs does and passes all the existing test cases. This will be added to npm once the version is stable.

Usage

mongots is easy to use:

// In typescript
import mongots = require('src/index');
import Database = require('src/lib/database');
var db : any = mongots(connectionString: string, [collections]: array<string>);

// Or use the javascript version directly
var mongots = require('mongots');
var db = mongots(connectionString, [collections]);

The connection string should follow the format described in the mongo connection string docs. Some examples of this could be:

// simple usage for a local db
var db = mongots('mydb', ['mycollection']);

// the db is on a remote server (the port default to mongo)
var db = mongots('example.com/mydb', ['mycollection']);

// we can also provide some credentials
var db = mongots('username:[email protected]/mydb', ['mycollection']);

// connect now, and worry about collections later
var db = mongots('mydb');
var mycollection = db.collection('mycollection');

After we connected we can query or update the database just how we would using the mongo API with the exception that we use a callback. The format for callbacks is always callback(error, value) where error is null if no exception has occured. The update methods save, remove, update and findAndModify also pass the lastErrorObject as the last argument to the callback function.

// find everything
db.mycollection.find(function(err, docs) {
	// docs is an array of all the documents in mycollection
});

// find everything, but sort by name
db.mycollection.find().sort({name:1}, function(err, docs) {
	// docs is now a sorted array
});

// iterate over all whose level is greater than 90.
db.mycollection.find({level:{$gt:90}}).forEach(function(err, doc) {
	if (!doc) {
		// we visited all docs in the collection
		return;
	}
	// doc is a document in the collection
});

// find a document using a native ObjectId
db.mycollection.findOne({
	_id:mongots.ObjectId('523209c4561c640000000001')
}, function(err, doc) {
	// doc._id.toString() === '523209c4561c640000000001'
});

// find all named 'mathias' and increment their level
db.mycollection.update({name:'mathias'}, {$inc:{level:1}}, {multi:true}, function() {
	// the update is complete
});

// find one named 'mathias', tag him as a contributor and return the modified doc
db.mycollection.findAndModify({
	query: { name: 'mathias' },
	update: { $set: { tag:'maintainer' } },
	new: true
}, function(err, doc, lastErrorObject) {
	// doc.tag === 'maintainer'
});


// use the save function to just save a document (callback is optional for all writes)
db.mycollection.save({created:'just now'});

If you provide a callback to find or any cursor config operation mongots will call toArray for you

db.mycollection.find({}, function(err, docs) { ... });

db.mycollection.find({}).limit(2).skip(1, function(err, docs) { ... });

is the same as

db.mycollection.find({}).toArray(function(err, docs) { ... });

db.mycollection.find({}).limit(2).skip(1).toArray(function(err, docs) { ... });

For more detailed information about the different usages of update and querying see the mongo docs

Events

var db = mongots('mydb', ['mycollection']);

db.on('error',function(err) {
	console.log('database error', err);
});

db.on('ready',function() {
	console.log('database connected');
});

Streaming cursors

All cursors are a readable stream of objects.

var JSONStream = require('JSONStream');

// pipe all documents in mycollection to stdout
db.mycollection.find({}).pipe(JSONStream.stringify()).pipe(process.stdout);

Notice that you should pipe the cursor through a stringifier (like JSONStream) if you want to pipe it to a serial stream like a http response.

Tailable cursors

If you are using a capped collection you can create a tailable cursor to that collection by adding tailable:true to the find options

var cursor = db.mycollection.find({}, {}, {tailable:true, timeout:false});

// since all cursors are streams we can just listen for data
cursor.on('data', function(doc) {
	console.log('new document', doc);
});

Note that you need to explicitly set the selection parameter in the find call.

Database commands

With mongots you can run database commands just like with the mongo shell using db.runCommand()

db.runCommand({ping:1}, function(err, res) {
	if(!err && res.ok) console.log("we're up");
});

or db.collection.runCommand()

db.things.runCommand('count', function(err, res) {
	console.log(res);
});

Bulk updates

Mongots supports the Bulk updates introduced in mongodb 2.6. Here's an example of the usage

var bulk = db.a.initializeOrderedBulkOp();
bulk.find({type: 'water'}).update({$set: {level: 1}});
bulk.find({type: 'water'}).update({$inc: {level: 2}});
bulk.insert({name: 'Spearow', type: 'flying'});
bulk.insert({name: 'Pidgeotto', type: 'flying'});
bulk.insert({name: 'Charmeleon', type: 'fire'});
bulk.find({type: 'flying'}).removeOne();
bulk.find({type: 'fire'}).remove();
bulk.find({type: 'water'}).updateOne({$set: {hp: 100}});

bulk.execute(function(err, res) {
  console.log('Done!');
});

Replication Sets

mongots can also connect to a mongo replication set by providing a connection string with multiple hosts

var db = mongots('rs-1.com,rs-2.com,rs-3.com/mydb?slaveOk=true', ['mycollection']);

For more detailed information about replica sets see the mongo replication docs

Using harmony features

If you run node.js with the --harmony option, then you can ommit the collection names array, and you can do stuff like.

var mongots = require('mongots');
var db = require('mydb');

db.hackers.insert({name: 'Ed'});

In the above example the hackers collection is enabled automagically (similar to the shell) using the Proxy feature in harmony

Passing a DB to the constructor

If you have an instance of mongots, you can pass this to the constructor and mongots will use the existing connection of that instance instead of creating a new one.

var mongodb = require('mongodb');
var mongots = require('mongots');

mongodb.Db.connect('mongodb://localhost/test', function(err, theDb) {
    var db = mongots(theDb, ['myCollection']);
});

Features not supported for MongoDB 2.4 or older (on mongots version 1.0+).

• Index creation and deletion
• Aggregation cursors.

This features are relatively easy to add, but would make the code unnecessarily more complex. If you are using mongodb 2.4 or older and would like to use mongots 1.0 with the above mentioned feautres, feel free to make a pull request or open and issue..

API

This API documentation is a work in progress.

Collection

#####db.collection.aggregate([pipeline], [callback])

#####db.collection.count([query], callback)

#####db.collection.createIndex(keys, options, [callback])

#####db.collection.distinct(field, query, callback)

#####db.collection.drop([callback])

#####db.collection.dropIndex(index, [callback])

#####db.collection.dropIndexes([callback])

#####db.collection.ensureIndex(keys, options, [callback])

#####db.collection.find([criteria], [projection], [callback])

This function applies a query to a collection. You can get the return value, which is a cursor, or pass a callback as the last parameter. Said callback receives (err, documents)

#####db.collection.findOne([criteria], [projection], callback)

Apply a query and get one single document passed as a callback. The callback receives (err, document)

#####db.collection.findAndModify(document, callback)

#####db.collection.getIndexes(callback)

#####db.collection.group(document, callback)

#####db.collection.insert(docOrDocs, [callback])

#####db.collection.isCapped(callback)

#####db.collection.mapReduce(map, reduce, options, [callback])

#####db.collection.reIndex([callback])

#####db.collection.remove(query, [justOne], [callback])

#####db.collection.runCommand(command, [callback])

#####db.collection.save(doc, [callback])

#####db.collection.stats(callback)

#####db.collection.update(query, update, [options], [callback])

#####db.collection.toString()

Get the name of the collection.

Cursor

#####cursor.batchSize(size, [callback])

#####cursor.count(callback)

#####cursor.explain(callback)

#####cursor.forEach(function)

#####cursor.limit(n, [callback])

#####cursor.map(function, [callback])

#####cursor.next(callback)

#####cursor.skip(n, [callback])

#####cursor.sort(sortOptions, [callback])

#####cursor.toArray(callback)

#####cursor.rewind()

#####cursor.destroy()

Database

#####db.addUser(document)

#####db.createCollection(name, options, [callback])

#####db.dropDatabase([callback])

#####db.eval(code, [params], [options], [callback])

#####db.getCollectionNames(callback)

#####db.getLastError(callback)

#####db.getLastErrorObj(callback)

#####db.removeUser(username, [callback])

#####db.runCommand(command, [callback])

#####db.stats([callback])

#####db.close()

Bulk

#####bulk.execute()

#####bulk.find(query)

#####bulk.find.remove()

#####bulk.find.removeOne()

#####bulk.find.replaceOne()

#####bulk.find.update(updaterParam)

#####bulk.find.updateOne(updaterParam)

#####bulk.find.upsert(upsertParam)

#####bulk.insert(document)

#####bulk.toString()