<?php
    define ('DBSERVER','localhost');
    define ('DBUSERNAME','root');
    define ('DBPASSWORD','');
    define ('DBNAME','demo');

    $db = new mysqli(DBSERVER, DBUSERNAME, DBPASSWORD, DBNAME);

    if($db===false)
      {  die('Error > connection error. '.$db->connect_error); }
?>