1、查询教师所有的单位即不重复的Depart列
select distinct depart from teacher
2、查询Score表中成绩在60到80之间的所有记录
select * from score where degree between 60 and 80
3、查询Score表中成绩为85,86或88的记录
select * from score where degree in (85,86,88)
4、查询Student表中“95031”班或性别为“女”的同学记录
select * from student where class='95031' or ssex ='女'
5、以Cno升序、Degree降序查询Score表的所有记录
select * from score order by cno,degree desc
6、查询“95031”班的学生人数
select count(*) from student where class='95031'
或者:select count(*) as scount from student where class='95031'
---查询结果另取列名 为scount 展示
7、查询Score表中的最高分的学生学号和课程号
select sno,cno from score where degree=(select max(degree) from score)
8、查询每门课的平均成绩
select cno,avg(degree) from score group by cno
9、查询Score表中至少有5名学生选修的并以3开头的课程的平均分数
select cno,avg(degree) from score group by cno having count(*)>=5 and cno like'3%'
10、查询所有学生的Sname、Cno和Degree列
select sname,cno,degree from student,score
where student.sno=score.sno
或者:select sname,cno,degree from score join student on score.sno = student.sno
11、查询所有学生的Sname、Cname和Degree列
select sname,cname,degree from student,course,score where student.sno = score.sno and score.cno=course.cno
或者:select sname,cname,degree from score join student on student.sno=score.sno join course on score.cno = course.cno
联系客服