Fatal error: Uncaught mysqli_sql_exception: Access denied for user 'root'@'localhost' (using password: NO) in /var/www/html/projects/barcode/barcode.php:3 Stack trace: #0 /var/www/html/projects/barcode/barcode.php(3): mysqli_connect() #1 {main} thrown in /var/www/html/projects/barcode/barcode.php on line 3