第二次作业1
需积分: 0 106 浏览量
2022-08-08
21:59:25
上传
评论
收藏 14KB DOCX 举报
第一题：
select *
from COURSES
第二题：
select distinct sid
from CHOICES
第三题：
select DISTINCT cid
from COURSES
where hour<88
第四题：
select sid, sname
from STUDENTS
where grade>400
第五题：
select COUNT(cid) as course_num
from COURSES
第六题：
select cid,COUNT(*)
from CHOICES
group by cid
第七题：
select sid
from CHOICES
where score>60
group by sid
having COUNT(*)>2
第八题：
select sid,COUNT(*) as total,AVG(score) as avg_score
from CHOICES
group by sid
第九题：
select sid,sname
from STUDENTS
where sid in(
评论0