Modella Mongo persistence layer

Usage no npm install needed!

<script type="module">
  import modellaMongo from '';



Build Status Coverage Status

Mongo plugin for modella. Thinly built on top of kissjs/node-mongoskin.


npm install modella-mongo


var model = require('modella');
    mongo = require('modella-mongo')('localhost/db');

var User = model('user')
  .attr('email', { unique: true })


 * Initialize

var user = new User;'matt'); {

Implemented Sync Layer Methods

By adding the plugin, modella 0.2.0 compliant sync layer methods are added. This enables instance#save() and instance#remove() to work with mongo.


By default, modella-mongo will use Model.modelName for the Collection. For example:

var mongo = require('modella-mongo')(connectionString);

var User = modella('User');
User.use(mongo); // Uses db.User

If you want, you can also specify a collection name yourself by passing it as a function to mongo. For example:

var mongo = require('modella-mongo')(connectionString);

var User = modella('User');
User.use(mongo('Account')); // Uses db.Account

Attribute Configuration

{'unique': true}

This will create a unique index for the attribute

False by default

{'atomic': true}

Uses the '$inc' update modifier for mongo, allowing a value to be (de)incremented as needed, rather than using '$set' each time.

This only works for number attributes.

False by default

{'type': 'type string or constructor'}

Since modella@0.2.9 the toJSON method is recursive. This causes objects that can be stored as one of mongodb's BSON types to be converted unecessarily into strings. To prevent this behavior, define types for attributes where appropriate. You do not need to do this for the _id attribute.

The currently available types are Dates and ObjectIds

var User = modella('User');

var mongo = require('modella-mongo')(connectionString);
// The ObjectID constructor is made available at mongo.ObjectId


    // This attribute will always be stored as an ObjectID in the database
    .attr('referredBy', {type: 'ObjectId'})
    // you can also use 'ObjectID' or the actual ObjectID constructor

    // This attribute will always be stroed as an ISODate object in the database
    .attr('joined', {type: 'date'});
    // you can also use the Date constructor

Using the constructor rather than a type string is recommended when using modella-mongo in conjunction with the modella-validators plugin.




An alias of the mongoskin.ObjectID constructor

Model Methods

By loading this plugin, Model inherits:


Object pointing to the raw mongoskin database. Use it to manipulate the collection directly.

Model#index(attr, options)

Index an attribute in mongo.

  User.index('email', { unique : true });

Alternatively, you can specify unique: true when defining an attribute.

User.attr('username', {unique: true});

// Equivilent to...
User.index('username', {unique: true, sparse: true});

Model.all(query, [options], fn)

Queries for all users in the collection that match the given query. Additional options can be passed in (eg. {sort: {age: -1}}).

Calls fn(err, instances) where instances is an array of Model instances. If no documents match, instances will be empty.

  User.all({emailConfirmed: true}, {sort: {emailConfirmationDate: 1}}, function(err, users) {
    console.log("Users with confirmed emails: ");
    users.forEach(function(u) {

Model.find/get(query, [options], fn)

Queries for one user in the collection that match the given query. Additional options can be passed in (eg. {sort: {age: -1}}).

query can also be a string, in which case it will be converted to an ObjectId.

Calls fn(err, instance) where instance is an instance of Model. If no documents match, instance will be false.

  User.get == User.find // true

  User.find('528263fa996abeabbe000002', function(err, u) {

Calls fn(err, instances) where instances is an array of Model instances. If no queries match, instances will be false.

Model.removeAll(query, [options], fn)

Removes all records that match the given query.

Calls fn(err, count) where count is the number of records removed. If no queries match, instances will be false.

  User.removeAll({emailConfirmed: false}, function(err, count) {
    console.log("%d users were deleted", count);


Returns a wrapped instances of mquery. See mquery support below.


Returns a wrapped instances of maggregate. See maggregate support below.

mquery support

modella-mongo provides a wrapped version of the wonderful mquery query builder. To get it, simply call Model.query(). This allows you to build readable and robust queries easily. When approprirate, modella-mongo will return instances of modella models, instead of just documents. Aside from that, it follows the mquery API completely.

Example with mquery

  User.query().findOne().where({username: 'Bob'}).exec(function(err, u) {
    u.username() // => 'Bob'

maggregate support

modella-mongo uses the maggregate aggregation builder. To use it, simply call Model.aggregate().

This allows you to build readable aggregations easily. By default it wraps responses in Model instances, but can be disabled by passing skipWrap as true. It also follows the maggregate api completely.

Example with maggregate

var skipWrapping = true;
User.aggregate(skipWrapping).group({_id: '$location', locationCount: {$sum: 1}}, function(err, res) {
  res.forEach(function(loc) {
    console.log("In location %s there are %d users", loc._id, loc.locationCount);

A Note about connection usage

Each call to modella-mongo will open up a mongo connection, and return a function that can be used as a plugin for ANY Modella model.

As such it is recommended that you export the result of modella-mongo and then use that for all of your models.

Example using too many connections

var mongo = require('modella-mongo')('localhost/my-db');
var mongo = require('modella-mongo')('localhost/my-db');

In the above example both the User and Post model will open a connection to the mongo database.

Example of better way

var mongo = module.exports = require('modella-mongo')('localhost/my-db');
var configuredDb = require('../config/modella-db');
var configuredDb = require('../config/modella-db');

Here modella-db.js configures the mongo database, and then both models use it.