问题描述: 用SQL语句如何列出各班平均成绩的前30%?班级在名为student的表上,各科成绩在名为score的表上. 1个回答 分类:综合 2014-09-30 问题解答: 我来补答 select * from student where sno in(select top 30 percent sno from score group by sno order by avg(grade) desc) 展开全文阅读