系统安全警告：MySql Error！

错误文件：/product3.php
错误信息：You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'and checkinfo='true' ORDER BY orderid asc' at line 1 Error sql: SELECT * FROM `ob_infoclass` WHERE parentid= and checkinfo='true' ORDER BY orderid asc