Fatal error: Uncaught mysqli_sql_exception: Unknown column 'index.html' in 'where clause' in /var/www/html/naming-dic/cate.html:19 Stack trace: #0 /var/www/html/naming-dic/cate.html(19): mysqli_query() #1 {main} thrown in /var/www/html/naming-dic/cate.html on line 19