SQL执行失败了，原因为：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 'order by class_id asc   limit  0 , 1' at line 1<p>SQL语句为：select class_name from wt_pic_class   where class_id=  order by class_id asc   limit  0 , 1</p>