Fatal error: Uncaught mysqli_sql_exception: Unknown database 'mainweb' in C:\xampp\htdocs\admin\functions\db.php:18 Stack trace: #0 C:\xampp\htdocs\admin\functions\db.php(18): mysqli_connect('localhost', 'root', Object(SensitiveParameterValue), 'mainweb') #1 C:\xampp\htdocs\index.php(2): require_once('C:\\xampp\\htdocs...') #2 {main} thrown in C:\xampp\htdocs\admin\functions\db.php on line 18