Warning: Undefined variable $mysqli in /customers/f/9/1/alagivskov.dk/httpd.www/mad/db_connect.php on line 5 Warning: Attempt to read property "connect_errno" on null in /customers/f/9/1/alagivskov.dk/httpd.www/mad/db_connect.php on line 5 Fatal error: Uncaught TypeError: mysqli_num_rows(): Argument #1 ($result) must be of type mysqli_result, bool given in /customers/f/9/1/alagivskov.dk/httpd.www/mad/kategorier.php:25 Stack trace: #0 /customers/f/9/1/alagivskov.dk/httpd.www/mad/kategorier.php(25): mysqli_num_rows(false) #1 {main} thrown in /customers/f/9/1/alagivskov.dk/httpd.www/mad/kategorier.php on line 25