Warning: Undefined variable $sql in /home/iltn/public_html/sqli2/2-db.php on line 21

Fatal error: Uncaught ValueError: PDO::prepare(): Argument #1 ($query) cannot be empty in /home/iltn/public_html/sqli2/2-db.php:21 Stack trace: #0 /home/iltn/public_html/sqli2/2-db.php(21): PDO->prepare('') #1 {main} thrown in /home/iltn/public_html/sqli2/2-db.php on line 21