Warning: Trying to access array offset on value of type null in /home/public/post.php on line 7

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 'LIMIT 1' at line 1 in /home/public/includes/public.php:45 Stack trace: #0 /home/public/includes/public.php(45): mysqli_query(Object(mysqli), 'SELECT username...') #1 /home/public/post.php(7): getAuthor(NULL) #2 {main} thrown in /home/public/includes/public.php on line 45