cara membuat login dengan mysql

? php require_once ("config. virtual office login php"); if (isset($_POST ['login'])){ $username = filter_input(INPUT_POST, 'username', FILTER_SANITIZE_STRING); $password = filter_input(INPUT_POST, 'password', FILTER_SANITIZE_STRING); $sql = "SELECT * FROM users WHERE username=:username OR email=:email"; $stmt = $db- prepare ($sql); // bind parameter ke query . tanda login