index.js

/* jshint strict: true */

'use strict';

var Promise = require('bluebird'),
  mysql = require('mysql2'),
  instances = {};

function DB() {
  this.pool = null;
}

/**
 * Setup the Database connection pool for this instance
 * @param  {Object} config
 */
DB.prototype.configure = function (config) {
  this.pool = mysql.createPool(config);
};

/**
 * Run DB query
 * @param  {String} query
 * @param  {Object} [params]
 * @return {Promise}
 */
DB.prototype.query = function (query, params) {
  var defer = Promise.defer();
  params = params || {};

  this.pool.getConnection(function (err, con) {
    if (err) {
      if (con) {
        con.release();
      }
      return defer.reject(err);
    }

    con.query(query, params, function (err) {
      if (err) {
        if (con) {
          con.release();
        }
        return defer.reject(err);
      }
      defer.resolve([].splice.call(arguments, 1));
      con.release();
    });
  });
  return defer.promise;
};

/**
 * Run DB execute
 * @param  {String} query
 * @param  {Object} [params]
 * @return {Promise}
 */
DB.prototype.execute = function (query, params) {
  var defer = Promise.defer();
  params = params || {};

  this.pool.getConnection(function (err, con) {
    if (err) {
      if (con) {
        con.release();
      }
      return defer.reject(err);
    }

    con.execute(query, params, function (err) {
      if (err) {
        if (con) {
          con.release();
        }
        return defer.reject(err);
      }
      defer.resolve([].splice.call(arguments, 1));
      con.release();
    });
  });
  return defer.promise;
};

module.exports = function (name) {
  name = name || '_default_';
  if (!instances[name]) {
    instances[name] = new DB();
  }
  return instances[name];
};