Connecting to Database

Before connecting, you will need a supported driver. Here's the drivers and versions that are tested, add the ones you need to your package.json.

driver	npm package	version
mysql	mysql	2.0.0-alpha8
postgres redshift	pg	~1.0.0
sqlite	sqlite3	2.1.7
mongodb	mongodb	1.3.11

These are the versions tested. Use others (older or newer) at your own risk.

For example, to use mysql just do:

npm install [email protected] --save

To connect to a database, you can pass a URL string where the scheme is a supported driver or you can pass an Object with the parameters of the connection.

var orm = require("orm");

orm.connect("mysql://root:password@localhost/test", function (err, db) {
    if (err) {
        console.log("Something is wrong with the connection", err);
        return;
    }

    // connected!
});

The callback is only called when the connection is done successfully (or unsuccessfully). You can avoid passing a callback and listen for the connect event if you prefer.

var orm = require("orm");
var db  = orm.connect("mysql://root:password@localhost/test");

orm.on("connect", function (err) {
    if (err) {
        console.log("Something is wrong with the connection", err);
        return;
    }

    // connected!
});

The connection URL has the following syntax: driver://username:password@hostname/database?option1=value1&option2=value2..

Valid options are:

• debug (default: false): prints queries to console;
• pool (default: false): manages a connection pool (only for mysql and postgres) using built-in driver pool;
• strdates (default: false): saves dates as strings (only for sqlite).

Both debug and pool can also be set using Settings.

Connecting to multiple databases

ORM Models are bound to database connections, so if you need 'multi-tenancy', that is need to connect to different servers or databases, you can use something like this:

// database.js

var connections = {};

function setup(db) {
  var User   = db.define('user', ...);
  var Shirt  = db.define('shirt', ...);
  Shirt.hasOne('user', User, ...);
}

module.exports = function (host, database, cb) {
  if (connections[host] && connections[host][database]) {
    return connections[host][database];
  }
  
  var opts = {
    host     : host,
    database : database,
    protocol : 'mysql',
    port     : '3306',
    query    : { pool: true }
  };
  
  orm.connect(opts, function (err, db) {
    if (err) return cb(err);
    
    connections[host] = connections[host] || {};
    connections[host][database] = db;
    setup(db);
    cb(null, db);
  });  
};

// somewhere else, eg, middleware

var database = require('./database');

database('dbserver1', 'main', function (err, db) {
  if (err) throw err;
  
  db.models.user.find(...);
  
  ...
});

Connections are cached, so models will only be defined once per server+database.
Because we're using a connection pool, we don't need to worry about running out of connections and we can run multiple queries at once.