SQL info: MySQL Query Error

Time: 2018-9-19 10:04am
Script: /huodong/fzxz/list.php

SQL: SELECT * FROM huodong_class WHERE parentid= AND ispass=1 AND zx=1 ORDER BY classid ASC
Error: 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 ispass=1 AND zx=1 ORDER BY classid ASC' at line 1
Errno.: 1064