出错信息：SQLSTATE[42000]: Syntax error or access violation: 1064 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 '-12,12' at line 1
出错SQL：select * from ex_product where pro_bigid=2 and pro_smallid=13 order by pro_index limit -12,12
出错文件地址：/weipai/muye.com.cn/inc/mysql_class.php
出错行号：181行
出错代码：42000