sql基础练习及答案总结

准备数据

建表语句

create table students
(sno varchar(3) not null, 
sname varchar(4) not null,
ssex varchar(2) not null, 
sbirthday datetime,
class varchar(5))

create table courses
(cno varchar(5) not null, 
cname varchar(10) not null, 
tno varchar(10) not null)

create table scores 
(sno varchar(3) not null, 
cno varchar(5) not null, 
degree numeric(10, 1) not null) 

create table teachers 
(tno varchar(3) not null, 
tname varchar(4) not null, tsex varchar(2) not null, 
tbirthday datetime not null, prof varchar(6), 
depart varchar(10) not null)

插入数据

insert into students (sno,sname,ssex,sbirthday,class) values (108 ,'曾华' ,'男' ,'1977-09-01',95033);
insert into students (sno,sname,ssex,sbirthday,class) values (105 ,'匡明' ,'男' ,'1975-10-02',95031);
insert into students (sno,sname,ssex,sbirthday,class) values (107 ,'王丽' ,'女' ,'1976-01-23',95033);
insert into students (sno,sname,ssex,sbirthday,class) values (101 ,'李军' ,'男' ,'1976-02-20',95033);
insert into students (sno,sname,ssex,sbirthday,class) values (109 ,'王芳' ,'女' ,'1975-02-10',95031);
insert into students (sno,sname,ssex,sbirthday,class) values (103 ,'陆君' ,'男' ,'1974-06-03',95031);

insert into courses(cno,cname,tno)values ('3-105' ,'计算机导论',825);
insert into courses(cno,cname,tno)values ('3-245' ,'操作系统' ,804);
insert into courses(cno,cname,tno)values ('6-166' ,'数据电路' ,856);
insert into courses(cno,cname,tno)values ('9-888' ,'高等数学' ,100);

insert into scores(sno,cno,degree)values (103,'3-245',86);
insert into scores(sno,cno,degree)values (105,'3-245',75);
insert into scores(sno,cno,degree)values (109,'3-245',68);
insert into scores(sno,cno,degree)values (103,'3-105',92);
insert into scores(sno,cno,degree)values (105,'3-105',88);
insert into scores(sno,cno,degree)values (109,'3-105',76);
insert into scores(sno,cno,degree)values (101,'3-105',64);
insert into scores(sno,cno,degree)values (107,'3-105',91);
insert into scores(sno,cno,degree)values (108,'3-105',78);
insert into scores(sno,cno,degree)values (101,'6-166',85);
insert into scores(sno,cno,degree)values (107,'6-106',79);
insert into scores(sno,cno,degree)values (108,'6-166',81);

insert into teachers(tno,tname,tsex,tbirthday,prof,depart) values (804,'李诚','男','1958-12-02','副教授','计算机系');
insert into teachers(tno,tname,tsex,tbirthday,prof,depart) values (856,'张旭','男','1969-03-12','讲师','电子工程系');
insert into teachers(tno,tname,tsex,tbirthday,prof,depart) values (825,'王萍','女','1972-05-05','助教','计算机系');
insert into teachers(tno,tname,tsex,tbirthday,prof,depart) values (831,'刘冰','女','1977-08-14','助教','电子工程系');

题目

1、 查询student表中的所有记录的sname、ssex和class列。
2、 查询教师所有的单位即不重复的depart列。
3、 查询student表的所有记录。
4、 查询score表中成绩在60到80之间的所有记录。
5、 查询score表中成绩为85，86或88的记录。
6、 查询student表中“95031”班或性别为“女”的同学记录。
7、 以class降序查询student表的所有记录。
8、 以cno升序、degree降序查询score表的所有记录。
9、 查询“95031”班的学生人数。
10、查询score表中的最高分的学生学号和课程号。
11、查询‘3-105’号课程的平均分。
12、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。
13、查询最低分大于70，最高分小于90的sno列。
14、查询所有学生的sname、cno和degree列。
15、查询所有学生的sno、cname和degree列。
16、查询所有学生的sname、cname和degree列。
17、查询“95033”班所选课程的平均分。
18、假设使用如下命令建立了一个grade表：
create table grade(low   number(3,0),upp   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’);
commit;
现查询所有同学的sno、cno和rank列。
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。
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。
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。
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。
23、查询“张旭“教师任课的学生成绩。
24、查询选修某课程的同学人数多于5人的教师姓名。
25、查询95033班和95031班全体学生的记录。
26、查询存在有85分以上成绩的课程cno.
27、查询出“计算机系“教师所教课程的成绩表。
28、查询“计算机系”与“电子工程系“不同职称的教师的tname和prof。
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。
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.
31、查询所有教师和同学的name、sex和birthday.
32、查询所有“女”教师和“女”同学的name、sex和birthday.
33、查询成绩比该课程平均成绩低的同学的成绩表。
34、查询所有任课教师的tname和depart.
35  查询所有未讲课的教师的tname和depart. 
36、查询至少有2名男生的班号。
37、查询student表中不姓“王”的同学记录。
38、查询student表中每个学生的姓名和年龄。
39、查询student表中最大和最小的sbirthday日期值。
40、以班号和年龄从大到小的顺序查询student表中的全部记录。
41、查询“男”教师及其所上的课程。
42、查询最高分同学的sno、cno和degree列。
43、查询和“李军”同性别的所有同学的sname.
44、查询和“李军”同性别并同班的同学sname.
45、查询所有选修“计算机导论”课程的“男”同学的成绩表

1.查询student表中的所有记录的sname、ssex和class列。

select sname,ssex,class
from student;

2.查询教师所有的单位即不重复的depart列。

select distinct depart
from teachers;

3.查询student表的所有记录。

select *
from students;

4.查询score表中成绩在60到80之间的所有记录。

select *
from scores
where degree between 60 and 80;

5.查询score表中成绩为85，86或88的记录。

select *
from scores
where degree in (85,86,88);

6.查询student表中“95031”班或性别为“女”的同学记录。

select *
from students
where class='95031' or ssex='女';

7.以class降序查询student表的所有记录。

select *
from students
order by class desc;

8.以cno升序、degree降序查询score表的所有记录。

select *
from scores
order by cno,degree desc;

9.查询“95031”班的学生人数。

select count(1) as stunum
from students
where class='95031';

10.查询score表中的最高分的学生学号和课程号。

select sno,cno
from scores
order by degree desc
limit 1;

11.查询‘3-105’号课程的平均分。

select avg(degree)
from scores
where cno='3-105';

12.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 scores
where cno like '3%'
group by cno
having count(sno) >= 5;

13.查询最低分大于70，最高分小于90的sno列。

select sno
from scores
group by sno
having max(degree)<90 and min(degree)>70;

14.查询所有学生的sname、cno和degree列。

select sname,cno,degree
from students inner join scores 
on(students.sno=scores.sno)
order by sname;

15.查询所有学生的sno、cname和degree列。

select sno,cname,degree
from scores inner join courses
on(scores.cno=courses.cno)
order by sno;

16.查询所有学生的sname、cname和degree列。

select sname,cname,degree
from students inner join scores
on(students.sno=scores.sno) inner join courses
on(scores.cno=courses.cno)
order by sname;

17.查询“95033”班所选课程的平均分。

select cname,avg(degree)
from students inner join scores
on(students.sno=scores.sno) inner join courses
on(scores.cno=courses.cno)
where class='95033'
group by courses.cno
order by cname;

18.假设使用如下命令建立了一个grade表：

create table grade(low tinyint,upp tinyint,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 sno,cno,rank
from scores inner join grade
on(scores.degree>=grade.low and scores.degree<=grade.upp)
order by sno;

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 s1.sno,s1.degree
from scores as s1 inner join scores as s2
on(s1.cno=s2.cno and s1.degree>s2.degree)
where s1.cno='3-105' and s2.sno='109'
order by s1.sno;

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 scores
group by sno
having count(cno)>1 and degree!=max(degree);

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。

select s1.sno,s1.degree
from scores as s1 inner join scores as s2
on(s1.cno=s2.cno and s1.degree>s2.degree)
where s1.cno='3-105' and s2.sno='109'
order by s1.sno;

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 s1.sno,s1.sname,s1.sbirthday
from students as s1 inner join students as s2
on(year(s1.sbirthday)=year(s2.sbirthday))
where s2.sno='108';

23.查询“张旭“教师任课的学生成绩。

select sno,degree
from scores inner join courses
on(scores.cno=courses.cno) inner join teachers
on(courses.tno=teachers.tno)
where teachers.tname='张旭';

24.查询选修某课程的同学人数多于5人的教师姓名。

select distinct tname
from scores inner join courses
on(scores.cno=courses.cno) inner join teachers
on(courses.tno=teachers.tno)
where courses.cno in(select cno from scores group by(cno) having count(sno)>5);

25.查询95033班和95031班全体学生的记录。

select *
from students
where class in ('95033','95031')
order by class;

26.查询存在有85分以上成绩的课程cno.

select distinct cno
from scores
where degree>85;

27.查询出“计算机系“教师所教课程的成绩表。

select tname,cname,sname,degree
from teachers inner join courses
on(teachers.tno=courses.tno) inner join scores
on(courses.cno=scores.cno) inner join students
on(scores.sno=students.sno)
where teachers.depart='计算机系'
order by tname,cname,degree desc;

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

29.查询选修编号为“3-105“课程且成绩至少高于任意选修编号为“3-245”的同学的成绩的cno、sno和degree,并按degree从高到低次序排序。

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

30.查询选修编号为“3-105”且成绩高于所有选修编号为“3-245”课程的同学的cno、sno和degree.

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

31.查询所有教师和同学的name、sex和birthday.

select sname,ssex,sbirthday
from students
union
select tname,tsex,tbirthday
from teachers;

32.查询所有“女”教师和“女”同学的name、sex和birthday.

select sname,ssex,sbirthday
from students
where ssex='女'
union
select tname,tsex,tbirthday
from teachers
where tsex='女';

33.查询成绩比该课程平均成绩低的同学的成绩表。

select s1.*
from scores as s1 inner join (
    select cno,avg(degree) as adegree
    from scores
    group by cno) s2
on(s1.cno=s2.cno and s1.degree34.查询所有任课教师的tname和depart.
select tname,depart
from teachers
where tno in(
    select tno
    from courses
);

35.查询所有未讲课的教师的tname和depart.
select tname,depart
from teachers
where tno not in(
    select tno
    from courses
);

36.查询至少有2名男生的班号。
select class,count(1) as boycount
from students
where ssex='男'
group by class
having boycount>=2;

37.查询student表中不姓“王”的同学记录。
select *
from students
where sname not like '王%';

38.查询student表中每个学生的姓名和年龄。
select sname,year(now())-year(sbirthday) as sage
from students;

39.查询student表中最大和最小的sbirthday日期值。
select min(sbirthday),max(sbirthday)
from students;

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 *
from students
order by class desc,sbirthday asc;

41.查询“男”教师及其所上的课程。
select teachers.tname,courses.cname
from teachers inner join courses
on(teachers.tno=courses.tno)
where teachers.tsex='男';

42.查询最高分同学的sno、cno和degree列。
select *
from scores
group by cno
having degree=max(degree);

43.查询和“李军”同性别的所有同学的sname.
select s1.sname
from students as s1 inner join students as s2
on(s1.ssex=s2.ssex)
where s2.sname='李军';

44.查询和“李军”同性别并同班的同学sname.
select s1.sname
from students as s1 inner join students as s2
on(s1.ssex=s2.ssex and s1.class=s2.class)
where s2.sname='李军';

45.查询所有选修“计算机导论”课程的“男”同学的成绩表
select *
from scores
where sno in (
    select sno
    from students
    where ssex='男') and
    cno in (
    select cno
    from courses
    where cname='计算机导论');
);>