Fatal error: Uncaught mysqli_sql_exception: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 1 in /home/apirnet2/ftp/uczelnie/uczelnia.php:53 Stack trace: #0 /home/apirnet2/ftp/uczelnie/uczelnia.php(53): mysqli->query('select nk from ...') #1 {main} thrown in /home/apirnet2/ftp/uczelnie/uczelnia.php on line 53