数据库出错: MySQL Query Error

Mysql error description: 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
Mysql error number: 1064
Date: 2019-08-18 @ 16:05
Query: SELECT `classname` FROM `ob3_class` WHERE `id` =
Script: http://www.chuqibuyi.com/blog/index.php?do=class&id=5&page=6