Fatal error: Uncaught TypeError: mysqli_num_rows(): Argument #1 ($result) must be of type mysqli_result, bool given in /var/www/html/mult_res/showdetail.php:24 Stack trace: #0 /var/www/html/mult_res/showdetail.php(24): mysqli_num_rows(false) #1 {main} thrown in /var/www/html/mult_res/showdetail.php on line 24