Asynchronous node connection object (prerequisites: Node v0.11.2+ using --harmony flag). To run, npm install, node --harmony main.js

connection.js

"use strict";

exports = module.exports = function(app) {
    var pool = app.get('pool'), Q = require('Q');

    return {
        execute: Q.async(function*(sql) {
            var params = Array.prototype.slice.call(arguments, 1);
            var deferred = Q.defer();

            try {
                pool.getConnection(function(err, connection) {
                    if (err) {
                        console.error(err);
                        // deferred.reject(err);
                        throw err;
                    }


                    connection.query(sql, params, function(err, results) {
                        connection.release();

                        if (err) {
                            console.error(err);
                            deferred.reject(err);
                        } else {
                            deferred.resolve((sql.indexOf('INSERT INTO') === 0 ? results.insertId : results));
                        }
                    });
                });
            } catch (err) {
                console.error(err);
                deferred.reject(err);
            }

            return deferred.promise;
        })
    }
}

main.js

"use strict";

var express = require('express'),
    app = express(),
    mysql = require('mysql'),
    Q = require('Q');

// --------------------------------------------
// Configuration
// --------------------------------------------
var pool = mysql.createPool({
    host: '',
    user: '',
    password: '',
    database: '',
});

app.set('pool', pool);
app.set('database', require('./lib/connection.js')(app));

app.use(express.logger());
app.use(express.json());
app.use(express.urlencoded());
app.use(express.methodOverride());
app.set('port', 3000);

app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));

app.use(app.router);

// --------------------------------------------
// Route for testing
// --------------------------------------------
app.get('/', Q.async(function*(req, res) {
    var db = app.get('database');

    var user = yield db.execute("SELECT * FROM users WHERE user_id=?", 1);

    return res.json(user);
}));


// --------------------------------------------
// Start server
// --------------------------------------------
app.listen(app.get('port'), function () {
  console.log('Express server listening on port ' + app.get('port'));
});

package.json

{
  "name": "async",
  "version": "0.0.0",
  "description": "",
  "main": "main.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Daniel Kleehammer",
  "license": "MIT",
  "dependencies": {
    "q": "~0.9.7",
    "mysql": "~2.0.0-rc2",
    "express": "~3.4.7"
  }
}