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 mysql@2.0.0-alpha8 --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).

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.