Fatal error: Uncaught mysqli_sql_exception: Unknown database 'database_name' in C:\xampp\htdocs\php test\upload.php:3 Stack trace: #0 C:\xampp\htdocs\php test\upload.php(3): mysqli->__construct('localhost', 'root', Object(SensitiveParameterValue), 'database_name') #1 {main} thrown in C:\xampp\htdocs\php test\upload.php on line 3