Fatal error: Uncaught mysqli_sql_exception: Access denied for user ''@'localhost' (using password: NO) in C:\xampp\htdocs\bateriasec\public\jqx\demos\PHP\listboxdata.php:7 Stack trace: #0 C:\xampp\htdocs\bateriasec\public\jqx\demos\PHP\listboxdata.php(7): mysqli->__construct('', '', '', '') #1 {main} thrown in C:\xampp\htdocs\bateriasec\public\jqx\demos\PHP\listboxdata.php on line 7