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/f5290126/domains/chat.mistereinstein.nl/public_html/core/functions.php:603 Stack trace: #0 /home/f5290126/domains/chat.mistereinstein.nl/public_html/core/functions.php(603): mysqli_query() #1 /home/f5290126/domains/chat.mistereinstein.nl/public_html/core/functions.php(703): user_isDocent() #2 /home/f5290126/domains/chat.mistereinstein.nl/public_html/index.php(19): user_hasChat() #3 {main} thrown in /home/f5290126/domains/chat.mistereinstein.nl/public_html/core/functions.php on line 603