Fatal error: Uncaught TypeError: mysqli_num_rows(): Argument #1 ($result) must be of type mysqli_result, bool given in /home/nnhoang/public_html/acad280/labs/lab11.php:18 Stack trace: #0 /home/nnhoang/public_html/acad280/labs/lab11.php(18): mysqli_num_rows(false) #1 {main} thrown in /home/nnhoang/public_html/acad280/labs/lab11.php on line 18