mysql 基礎練習題(一)

一、先創建幾個要用的庫表

create database zuoye;      -- 創建數據庫
use zuoye;      -- 使用數據庫


#創建幾個庫表
create table Student    -- 學生表
(
Sno char(3) NOT NULL Primary key ,    -- 學號 ，設為主鍵，不允許空值   
Sname char(8) NOT NULL,        -- 學生姓名
Ssex char(2)NOT NULL,        -- 學生性別
Sbirthday datetime,     -- 學生出生年月
Class char(5)         -- 學生所在班級
);

create table Teacher        -- 教師表
(
Tno char(3)NOT NULL primary key,        -- 教工編號設為主鍵
Tname char(4)NOT NULL,        -- 教工姓名
Tsex char(2)NOT NULL,        -- 教工性別
Tbirthday datetime,        -- 教工出生年月
Prof char(6),        -- 職稱
Depart varchar(10)NOT NULL        -- 教工所在部門
)

create table Course        -- 課程表
(
    Cno char(5) NOT NULL Primary key ,        -- 課程號設為主鍵
    Cname varchar(10) NOT NULL,        -- 課程名稱
    Tno char(3) NOT NULL references Teacher(Tno)        -- 教工編號設為外鍵
)

create table Score    -- 成績表
(
Sno char(3) NOT NULL references Student(Sno),    -- 學號設為外碼
Cno char(5) NOT NULL references Course(Cno),    -- 課程號設為外碼
Degree Decimal(4,1),    -- 成績
primary key(Sno,Cno)    -- 學號和課程號設為聯合主鍵
)

二、插入數據

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

insert into Teacher values(804,'李誠','男','1958-12-02','副教授','計算機系');
insert into Teacher values(856,'張旭','男','1969-03-12','講師','電子工程系');
insert into Teacher values(825,'王萍','女','1972-05-05','助教','計算機系') ;
insert into Teacher values(831,'劉冰','女','1977-08-14','助教','電子工程系');

insert into Course values('3-105','計算機導論',825);
insert into Course values('3-245','操作系統',804);
insert into Course values('6-166','數字電路',856);
insert into Course values('9-888','高等數學',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、查詢練習（重點）

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

 

1~10題：

-- 1、 查詢Student表中的所有記錄的Sname、Ssex和Class列。
-- 2、 查詢教師所有的單位即不重復的Depart列。
-- 3、 查詢Student表的所有記錄。
-- 4、 查詢Score表中成績在60到80之間的所有記錄。
-- 5、 查詢Score表中成績為85，86或88的記錄。

-- 6、 查詢Student表中"95031"班或性別為"女"的同學記錄。
-- 7、 以Class降序查詢Student表的所有記錄。
-- 8、 以Cno升序、Degree降序查詢Score表的所有記錄。
-- 9、 查詢"95031"班的學生人數。
-- 10、 查詢Score表中的最高分的學生學號和課程號。（子查詢或者排序）
-- 10.1 查詢Score表中除了每門課程最高分的學生學號和課程號。（子查詢或者排序） 

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題：

-- 11、查詢每門課的平均成績。
-- 12、查詢Score表中至少有5名學生選修的並以3開頭的課程的平均分數。
-- 13、查詢分數大於70，小於90的Sno列。
-- 14、查詢所有學生的Sname、Cno和Degree列。 
-- 15、查詢所有學生的Sno、Cname和Degree列。
-- 16、查詢所有學生的Sname、Cname和Degree列。
-- 17、查詢"95033"班學生的平均分。

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、 現查詢所有同學的Sno、Cno和rank列。
-- 19、查詢選修"3-105"課程的,並且成績高於"109"號同學成績的所有同學的記錄。

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題：

-- 20、查詢成績高於學號為"109"、課程號為"3-105"的成績的所有記錄。
-- 21、查詢和學號為109的同學同年出生的所有學生的Sno、Sname和Sbirthday列。
-- 22、查詢"張旭"教師任課的學生成績。
-- 23、查詢選修某課程的同學人數多於5人的教師姓名。
-- 24、查詢95033班和95031班全體學生的記錄。
-- 25、查詢存在有85分以上成績的課程Cno。
-- 26、查詢出"計算機系"教師所教課程的成績表。
-- 27、查詢選修編號為"3-105"課程且成績至少高於一個選修編號為"3-245"的同學的Cno、Sno和Degree,並按Degree從高到低次序排序。
-- 28、查詢選修編號為"3-105"且成績高於選修編號為"3-245"課程的同學的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 = "張旭"));
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 = "計算機系"));
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題：

 -- 31、查詢所有教師和同學的name、sex和birthday。
 -- 32、查詢所有"女"教師和"女"同學的name、sex和birthday。
 -- 33、查詢成績比該課程平均成績低的同學的成績表。
 -- 34、查詢所有任課教師的Tname和Depart。
 -- 35、查詢所有任課教師的Tsex和Tbirthday。
 -- 36、查詢至少有2名男生的班號。
 -- 37、查詢Student表中不姓"王"的同學記錄。
 -- 38、查詢Student表中每個學生的姓名和年齡。
 -- 39、查詢Student表中最大和最小的Sbirthday日期值。
 -- 40、以班號和年齡從大到小的順序查詢Student表中的全部記錄。

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題： 

-- 41、查詢"男"教師及其所上的課程。
-- 42、查詢最高分同學的Sno、Cno和Degree列。
-- 43、查詢和"李軍"同性別的所有同學的Sname。
-- 44、查詢和"李軍"同性別並同班的同學Sname。
-- 45、查詢所有選修"計算機導論"課程的"男"同學的成績表。

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="李軍");
44. select sname from Student where ssex=(select ssex from Student where sname="李軍") and class=(select class from Student where sname="李軍");
45. select * from Score where sno in (select sno from Student where ssex="男") and cno = (select cno from Course where Cname="計算機導論");