SQL语句求解答，急！！
select student.stumajor,sc.stuclass,sc.stunumber,student.stuname,SUM(scgrade) as allcout from sc,student where sc.stunumber=student.stunumber and sc.stuclass='班级' and stumajor='专业'group by sc.stunumber,stuname,sc.stuclass,student.stumajor order by SUM(scgrade) desc

就是想将一个班级的同学的总成绩进行排序
但是我加上 and sc.stuclass='班级' and stumajor='专业' 就显示不出来

打错字了，自己的帖子都不能编辑，BS一下CSDN。