mysql 基础练习题(一)

一、先创建几个要用的库表

create database zuoye;      -- 创建数据库
use zuoye;      -- 使用数据库


#创建几个库表
create table Student    -- 学生表
(
Sno char(3) NOT NULL Primary key ,    -- 学号 ，设为主键，不允许空值   
Sname char(8) NOT NULL,        -- 学生姓名
Ssex char(2)NOT NULL,        -- 学生性别
Sbirthday datetime,     -- 学生出生年月
Class char(5)         -- 学生所在班级
);

create table Teacher        -- 教师表
(
Tno char(3)NOT NULL primary key,        -- 教工编号设为主键
Tname char(4)NOT NULL,        -- 教工姓名
Tsex char(2)NOT NULL,        -- 教工性别
Tbirthday datetime,        -- 教工出生年月
Prof char(6),        -- 职称
Depart varchar(10)NOT NULL        -- 教工所在部门
)

create table Course        -- 课程表
(
    Cno char(5) NOT NULL Primary key ,        -- 课程号设为主键
    Cname varchar(10) NOT NULL,        -- 课程名称
    Tno char(3) NOT NULL references Teacher(Tno)        -- 教工编号设为外键
)

create table Score    -- 成绩表
(
Sno char(3) NOT NULL references Student(Sno),    -- 学号设为外码
Cno char(5) NOT NULL references Course(Cno),    -- 课程号设为外码
Degree Decimal(4,1),    -- 成绩
primary key(Sno,Cno)    -- 学号和课程号设为联合主键
)

二、插入数据

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

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

insert into Course values('3-105','计算机导论',825);
insert into Course values('3-245','操作系统',804);
insert into Course values('6-166','数字电路',856);
insert into Course values('9-888','高等数学',831);

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

三、查询练习（重点）

select * from Student;
select * from Teacher;
select * from Course;
select * from Score;

 

1~10题：

-- 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。（子查询或者排序）
-- 10.1 查询Score表中除了每门课程最高分的学生学号和课程号。（子查询或者排序） 

1. select sname, ssex, class from Student;
2. select distinct depart from Teacher;
3. select * from Student;
4. select * from Score where degree  between  60 and 80;
5. select * from Score where degree in (85,86,88);
6. select * from Student where class = '95031' or ssex = '女';
7. select * from Student order by class desc;
8. select * from Score order by cno, degree desc;
9. select count(sno) from Student where class = 95031;
10. select sno,cno from Score where  degree = (select max(degree) from Score);
10.1 select sno,cno from Score where  degree != (select max(degree) from Score);

11~17题：

-- 11、查询每门课的平均成绩。
-- 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、查询分数大于70，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"班学生的平均分。

11. select  cno,avg(degree) from Score group by cno;
12. select cno,avg(degree) from Score  where cno in (select cno from Score  where cno like "3%"  group by cno  having count(cno) >=5 ) group by cno;
13. select * from Score where degree between 70 and 90;
14. select st.sname,sc.cno,sc.degree from Student st left join Score sc on st.sno = sc.sno;
15. select sc.sno,co.cname,sc.degree from Score sc left join Course co on sc.cno = co.cno;
16. select st.sname,co.cname,sc.degree from Student st left join Score sc on st.sno = sc.sno left join Course co on sc.cno = co.cno;
17. select avg(degree) from Score where sno in (select sno from Student where class = 95033);

create table Grade(Low int  ,Upp int,Rank char(1))
select *from Grade;
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');

--18、 现查询所有同学的Sno、Cno和rank列。
-- 19、查询选修"3-105"课程的,并且成绩高于"109"号同学成绩的所有同学的记录。

18.
      select s.sname,s.sno, s.degree,
      (case 
       when s.degree between 90 and 100 then 'A'
       when s.degree between 80 and 89 then 'B' 
       when s.degree between 70 and 79 then 'C'
       when s.degree between 60 and 69 then 'D'
       when s.degree between 0 and 59 then 'E'
       end) as rank
       from
      (select st.sname, sc.sno,sc.degree
       from
       Student st
       left join Score sc on st.sno = sc.sno) s;

19. select * from  Score where cno = "3-105" and degree > (select degree from Score where cno = "3-105" and sno = 109); 

 20-28题：

-- 20、查询成绩高于学号为"109"、课程号为"3-105"的成绩的所有记录。
-- 21、查询和学号为109的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
-- 22、查询"张旭"教师任课的学生成绩。
-- 23、查询选修某课程的同学人数多于5人的教师姓名。
-- 24、查询95033班和95031班全体学生的记录。
-- 25、查询存在有85分以上成绩的课程Cno。
-- 26、查询出"计算机系"教师所教课程的成绩表。
-- 27、查询选修编号为"3-105"课程且成绩至少高于一个选修编号为"3-245"的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。
-- 28、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。

20. select * from  Score where cno ="3-105" and degree > (select degree from Score where cno = "3-105" and sno = 109);
21. select sno,sname,sbirthday from Student where substr(sbirthday,1,4) = (select substr(sbirthday,1,4) as `st.year` from Student where sno = 109);  或 
    select sno,sname,sbirthday from Student where year(sbirthday) = (select year(sbirthday) as `st.year` from Student where sno = 109);
22. select sno,degree from Score where cno = (select cno from Course where tno = (select tno from Teacher where tname = "张旭"));
23. select tname from Teacher where tno in (select  tno from Course where cno in (select cno from Score group by cno having count(cno) >5));
24. select * from Student where class in (95033,95031);
25. select distinct cno from Score where degree >=85;
26. select * from Score where cno in (select cno from Course where tno in (select tno from Teacher where depart = "计算机系"));
27. select * from Score where cno = "3-105"  and degree > any (select degree from Score where cno = "3-245" ) order by degree desc;
28. select * from Score where cno = "3-105"  and degree > all (select degree from Score where cno = "3-245" );

 31-40题：

 -- 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、查询所有任课教师的Tsex和Tbirthday。
 -- 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。

31. select sname,ssex,sbirthday from Student union  select tname,tsex,tbirthday from Teacher;
32. select * from (select sname,ssex,sbirthday from Student  union  select tname,tsex,tbirthday from Teacher) a  where a.ssex ="女";
33. select * from Score s1 where degree < (select avg(degree) from Score s2 group by cno having s1.cno = s2.cno );
34. select tname,depart from Teacher;
35. select tsex,tbirthday from Teacher;
36. select class from Student where ssex = '男' group by class having count(*) >=2;
37. select * from Student where sname not like "王%";
38. select sname,year(now()) - year(sbirthday) as sage from Student;
39. select max(sbirthday),min(sbirthday)  from Student;
40. select * from Student order by class desc,now() - sbirthday desc;

41-45题： 

-- 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。

41. select te.tname,co.cname from Teacher te inner join Course co on  te.tsex="男" and te.tno = co.tno;
42. select * from Score where degree in  (select max(degree) from Score);
43. select sname from Student where ssex=(select ssex from Student where sname="李军");
44. select sname from Student where ssex=(select ssex from Student where sname="李军") and class=(select class from Student where sname="李军");
45. 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");