Fatal error: Uncaught TypeError: mysqli_num_rows(): Argument #1 ($result) must be of type mysqli_result, bool given in /home/sandelz/public_html/graph_app/test.php:25 Stack trace: #0 /home/sandelz/public_html/graph_app/test.php(25): mysqli_num_rows(false) #1 {main} thrown in /home/sandelz/public_html/graph_app/test.php on line 25