烟台万达附近的宾馆:实验四

来源:百度文库 编辑:偶看新闻 时间:2024/04/29 14:30:02

select count(sno)'总人数'
from student
select count(sno)'选修了课程人数'
from sc
group by sno

select count(distinct sno)'选修了课程人数'
from sc

select cno'课号',count(sno)'人数'
from sc
group by cno