18、假设使用如下命令建立了一个grade表：

create table grade(low number(3,0),up number(3),rank char(1));

insert into grade values(90,100,’A’);

insert into grade values(80,89,’B’);

insert into grade values(70,79,’C’);

insert into grade values(60,69,’D’);

insert into grade values(0,59,’E’);

现查询所有同学的Sno、Cno和rank列

select sc.sno,sc.cno,g.rank from score sc
join grade g
on/where sc.degree between g.low and g.up;

题目18

19、查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录

select a.* from score a where a.cno='3-105' and a.degree>all(select degree
from score b where b.sno='109' and b.cno='3-105');

题目19

20、查询score中选学一门以上课程的同学中分数为非最高分成绩的记录

select * from score sc where degree<(select max(degree) from score) 
group by sno having count(sno)>1
order by degree;

题目20

21、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录
<b>同19题</b>
22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列

select sno,sname,sbirthday from student where year(sbirthday)=
(select year(sbirthday) from student where sno='108');

题目22

23、查询“张旭“教师任课的学生成绩

select sc.sno,sc.degree from score sc
join(teacher t,course c)
on sc.cno=c.cno and t.tno=c.tno
where t.tname='张旭';

题目23

24、查询选修某课程的同学人数多于5人的教师姓名

 select t.tname from teacher t join (course c,score sc)
 on (t.tno=c.tno and c.cno=sc.cno)
 group by sc.cno having count(sc.cno) >5;

题目24

25、查询95033班和95031班全体学生的记录

select * from student
where class in ('95033','95031');

题目25

26、查询存在有85分以上成绩的课程Cno

解法一

select distinct cno from score where degree > 85;

解法二

 select cno from score group by cno having max(degree)>85;

题目26

27、查询出“计算机系“教师所教课程的成绩表

解法一

select sc.* from score sc
join (teacher t,course c)
on sc.cno = c.cno and t.tno=c.tno
where t.depart = '计算机系';

解法二

select * from score where cno in
(select c.cno from course c join teacher t
on c.tno=t.tno and t.depart='计算机系');

题目27

28、查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof

 select tname,prof from teacher 
where depart='计算机系' and prof not in 
(select prof from teacher where depart='电子工程系');

题目28

29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。

select cno,sno,degree from score
where degree >=(select min(degree) from score where cno='3-245')
<!-- any(select degree)-->
and cno='3-105'
order by degree desc;

题目29

30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree.

select cno,sno,degree from score
where degree >=(select max(degree) from score where cno='3-245')
and cno='3-105'
order by degree desc;

题目30

31、查询所有教师和同学的name、sex和birthday.

<!-- as 可以去掉-->
select sname as name,ssex as sex,sbirthday as birthday from student
union
select tname as name,tsex as sex,tbirthday as birthday from teacher;

题目31

32、查询所有“女”教师和“女”同学的name、sex和birthday.

<!-- as 可以去掉-->
select sname as name,ssex as sex,sbirthday as birthday from student
where ssex = '女'
union
select tname as name,tsex as sex,tbirthday as birthday from teacher
where tsex = '女';

题目32

33、查询成绩比该课程平均成绩低的同学的成绩表。

select sc.* from score sc 
where degree <(select avg(degree) from score sc2 
where sc.cno=sc2.cno);

题目33

34、查询所有任课教师的Tname和Depart.

select t.tname,t.depart from teacher t 
join course c on t.tno=c.tno;

题目34

35、查询所有未讲课的教师的Tname和Depart.

关联字段名相同可用using，等同于 a.字段1=b.字段1

select tname,depart from teacher t 
left join course c using(tno) where isnull (c.tno);

题目35

36、查询至少有2名男生的班号。

select class from student s where ssex='男'
group by class having count(ssex)>1;

题目36

37、查询Student表中不姓“王”的同学记录

select * from student where sname not like '王%';

题目37

38、查询Student表中每个学生的姓名和年龄

 select sname,(year(now())-year(sbirthday)) age from student;

题目38

39、查询Student表中最大和最小的Sbirthday日期值

select sname,sbirthday from student where sbirthday = (select max(sbirthday) from student) 
union
select sname,sbirthday from student where sbirthday = (select min(sbirthday) 
from student);

题目39

40、以班号和年龄从大到小的顺序查询Student表中的全部记录

select class,(year(now())-year(sbirthday)) age from student 
order by class desc,age desc;

题目40

41、查询“男”教师及其所上的课程

select t.tname,c.cname from teacher t 
join course c using(tno) where t.tsex='男';

题目41

42、查询最高分同学的Sno、Cno和Degree列

select sno,cno,degree from score 
where degree = (select max(degree) from score);

题目42

43、查询和“李军”同性别的所有同学的Sname

select sname from student
where ssex = (select ssex from student where sname='李军');

select s.sname from student s
where ssex = (select s2.ssex from student s2 where s2.sname='李军');

题目43

44、查询和“李军”同性别并同班的同学Sname.

select sname from student 
where ssex=(select ssex from student where sname='李军')
and class=(select class from student where sname='李军');

select a.sname from student a
where ssex=(select b.ssex from student b where b.sname='李军')
and class=(select c.class from student c where c.sname='李军');

题目44

45、查询所有选修“计算机导论”课程的“男”同学的成绩表

解法1

select * from score 
where sno in(select sno from student where ssex='男') 
and cno=(select cno from course where cname='计算机导论');

解法2

select sc.* from score sc
join (student s,course c) using(sno,cno)
where s.ssex='男'and c.cname='计算机导论';

题目45