text: var path = require('path');
  
  //Postgres DATABASE_URL= postgres://...
  //DQLite   DATABASE_URL= sqlite://:@:/
  var url = process.env.DATABASE_URL.match(/(.*)\:\/\/(.*?)\:(.*)@(.*)\:(.*)\/(.*)/);
  var DB_name     = (url[6]||null);
  var user		= (url[2]||null);
  var pwd			= (url[3]||null);
  var protocol    = (url[1]||null);
  var dialect     = (url[1]||null);
  var port		= (url[5]||null);
  var host 		= (url[4]||null);
  var storage     = process.env.DATABASE_STORAGE;
  
  //cargar modelo ORM
  var Sequelize = require('sequelize');
  
  //Usar bbdd sqlite:
  var sequelize = new Sequelize(DB_name,user,pwd,
  					{
  						dialect: 	dialect,
  						protocol: 	protocol,
  						port: 		port,
  						host: 		host,
  						storage: 	storage,
  						omitNull: 	true
  					}
  					);
  
  //importar definición de la tabla quiz.js:
  var quiz_path = path.join(__dirname,'quiz');
  var Quiz = sequelize.import(quiz_path);
  
  //importar definición de la tabla Comment.js:
  var comment_path = path.join(__dirname,'comment');
  var Comment = sequelize.import(comment_path);
  
  //Establecer relación entre quiz y comment 1 a N:
  Comment.belongsTo(Quiz);
  Quiz.hasMany(Comment);
  
  exports.Quiz = Quiz; //exportar definición de Quiz.
  exports.Comment = Comment; //exportar definición de Comment.
  
  //sequelize.sync crea e inicializa la tabla:
  sequelize.sync().then(function() {
  	Quiz.count().then(function (count) {
  		if (count===0) {
  			Quiz.create({ pregunta: 'Capital de Italia',
  						  respuesta: 'Roma',
  						  tema: 'Humanidades'
  						});
  			Quiz.create({ pregunta: 'Capital de Portugal',
  						  respuesta: 'Lisboa',
  						  tema: 'Humanidades'
  						})
  			.success(function(){console.log('Base de datos inicializada')});
  		};
  	});
  });