public function execute()
 {
     try {
         $where = null;
         $fields = array(usuarioCredencialTableClass::ID);
         $fields2 = array(usuarioTableClass::USER);
         $fields3 = array(credencialTableClass::NOMBRE);
         $fJoin1 = usuarioCredencialTableClass::USUARIO_ID;
         $fJoin2 = usuarioTableClass::ID;
         $fJoin3 = usuarioCredencialTableClass::CREDENCIAL_ID;
         $fJoin4 = credencialTableClass::ID;
         $orderBy = array(usuarioCredencialTableClass::ID);
         $page = 0;
         if (request::getInstance()->hasGet('page')) {
             $page = request::getInstance()->getGet('page') - 1;
             $page = $page * config::getRowGrid();
         }
         $f = array(usuarioCredencialTableClass::ID);
         if (request::getInstance()->hasGet('page')) {
             $this->page = request::getInstance()->getGet('page');
         } else {
             $this->page = $page;
         }
         $lines = config::getRowGrid();
         $this->cntPages = usuarioCredencialTableClass::getAllCount($f, true, $lines, $where);
         $this->objUsuCrede = usuarioCredencialTableClass::getAllJoin($fields, $fields2, $fields3, null, $fJoin1, $fJoin2, $fJoin3, $fJoin4, null, null, false, $orderBy, 'ASC', config::getRowGrid(), $page, $where);
         $this->defineView('index', 'usuarioCredencial', session::getInstance()->getFormatOutput());
     } catch (PDOException $exc) {
         echo $exc->getMessage();
         echo '<br>';
         echo '<pre>';
         print_r($exc->getTrace());
         echo '</pre>';
     }
 }