MySQL查詢語句實操練習

題目:新建一個資料庫ClassManager，包括四個表：學生表（Student）、課程表（Course）、成績表（Score）以及教師信息表（Teacher）。四個表的結構分別如表1-1的表（一）~表（四）所示，數據如表1-2的表（一）~表（四）所示。用SQL語句創建四個表並完成相關題目。

一.表1-1資料庫的表結構

表（一）Student (學生表) 

表（二）Course（課程表）

表（三）Score(成績表)

表（四）Teacher(教師表)

二.表1-2資料庫中的數據

表（一）Student

表（二）Course

表（三）Score

表（四）Teacher

三.完成以下操作

0.根據上述題目和表格，創建相應資料庫，創建相應表結構，並插入給定數據

create database ClassManager；
use ClassManager1;

create table student (
sno varchar(20) not null comment '學號',
sname varchar(20) not null comment '學生姓名',
ssex varchar(20) not null comment '學生性別',
sbirthday datetime comment '學生出生年月',
class varchar(20) comment '學生所在班級'
);

create table course (
cno varchar(20) not null comment '課程號',
cname varchar(20) not null comment '課程名稱',
tno varchar(20) not null comment '教工編號'
);

create table score (
sno varchar(20) not null comment '學號',
cno varchar(20) not null comment '課程號',
degree decimal(4,1) comment '成績'
);

create table teacher (
tno varchar(20) not null comment '教工編號',
tname varchar(20) not null comment '教工姓名',
tsex varchar(20) not null comment '教工性別',
tbirthday datetime comment '教工出生年月',
prof varchar(20) comment '職稱',
depart varchar(20) not null comment '教工所在部門'
);

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

insert into course (cno, cname, tno) values ('3-105', '電腦導論',  '825');
insert into course (cno, cname, tno) values ('3-245', '操作系統',    '804');
insert into course (cno, cname, tno) values ('6-166', '數字電路',    '856');
insert into course (cno, cname, tno) values ('9-888', '高等數學',    '831');

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


insert into teacher (tno, tname, tsex, tbirthday, prof, depart) values ('804', '李誠','男','1958-12-02','副教授','電腦系');
insert into teacher (tno, tname, tsex, tbirthday, prof, depart) values ('856', '張旭','男','1969-03-12','講師','電子工程系');
insert into teacher (tno, tname, tsex, tbirthday, prof, depart) values ('825', '王萍','女','1972-05-05','助教','電腦系');
insert into teacher (tno, tname, tsex, tbirthday, prof, depart) values ('831', '劉冰','女','1977-08-14','助教','電子工程系');

1. 查詢Student表中的所有記錄的Sname、Ssex和Class列。

select sname, ssex, class from student;

2. 查詢教師所有的單位即不重覆的Depart列。

select distinct depart from teacher;

3. 查詢Student表的所有記錄。

select * from student;

4. 查詢Score表中成績在60到80之間的所有記錄。

select * from score where degree between 60 and 80;

5. 查詢Score表中成績為85，86或88的記錄。

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

6. 查詢Student表中“95031”班或性別為“女”的同學記錄。

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

7. 以Class降序查詢Student表的所有記錄。

select * from student order by class desc;

8. 以Cno升序、Degree降序查詢Score表的所有記錄。

select * from score order by cno asc, degree desc;

9. 查詢“95031”班的學生人數。

select count(*) from student where class = '95031';

10.查詢Score表中的最高分的學生學號和課程號。

select * from score sc  where degree = (select max(degree) as max from score where cno = sc.cno group by cno);

11.查詢每門課的平均成績。

select cno, avg(degree) as avg from score group by cno;

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。

select cno, avg(degree) as avg from score where cno like '3%' group by cno having count(*) >= 5;

13.查詢分數大於70，小於90的Sno列。

select sno from score where degree > 70 and degree < 90;

14.查詢所有學生的Sname、Cno和Degree列。

select sname, cno, degree from student s left join score sc on sc.sno = s.sno;

15.查詢所有學生的Sno、Cname和Degree列。

select s.sno, c.cname, sc.degree from student s left join score sc on sc.sno = s.sno left join course c on c.cno = sc.cno;

16.查詢所有學生的Sname、Cname和Degree列。

select s.sname, c.cname, sc.degree from student s left join score sc on sc.sno = s.sno left join course c on c.cno = sc.cno;

17.查詢“95033”班學生的平均分。

select cno , avg(degree)  from score sc where sc.sno in (select sno from student where class = '95033') group by cno;

18.查詢選修“3-105”課程的成績高於“109”號同學成績的所有同學的記錄。

select * from score where sno = '109' and cno = '3-105';

19.查詢成績高於學號為“109”、課程號為“3-105”的成績的所有記錄。

select * from score where  cno = '3-105' and degree > (select degree from score where sno = '109'and cno = '3-105'); -- 此處理解為只看‘3-105’課程成績
select * from score where degree > (select degree from score where sno = '109'and cno = '3-105'); -- 此處為各科成績都算。

20.查詢和學號為108、101的同學同年出生的所有學生的Sno、Sname和Sbirthday列。(使用year()方法對生日欄位求年份)

select sno,sname,sbirthday from student where year(sbirthday) in (select year(sbirthday) from student where sno in ('108', '101'));

21.查詢“張旭“教師任課的學生成績。

select sc.* from score sc inner join course c on c.cno = sc.cno inner join teacher t on t.tno = c.tno where t.tname = '張旭'; -- 合併多個表然後查詢
select * from score where cno in(select cno from course where tno in(select tno from teacher where tname ='張旭')); -- 嵌套查詢

22.查詢選修某課程的同學人數多於5人的教師姓名。

select tname from teacher where tno = (select tno from course where cno = (select cno from score group by cno having count(*) > 5));

23.查詢95033班和95031班全體學生的記錄。

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

24.查詢存在有85分以上成績的課程Cno。

select distinct cno from score where degree > 85;

25.查詢出“電腦系“教師所教課程的成績表。

select * from score where cno in (select cno from course where tno in (select tno from teacher where depart = '電腦系')); 

26.查詢“計算 機系”與“電子工程系“不同職稱的教師的Tname和Prof。

select tname, prof from teacher where depart = '電腦系' and prof not in (select prof from teacher where depart = '電子工程系')union select tname, prof from teacher where depart = '電子工程系' and prof not in (select prof from teacher where depart = '電腦系');

27.查詢所有教師和同學的name、sex和birthday。

select sname as `name`, ssex as `sex`, sbirthday as `birthday` from student union select tname, tsex,tbirthday from teacher;

28.查詢所有“女”教師和“女”同學的name、sex和birthday。

select sname as `name` , ssex as `sex`, sbirthday as `birthday`from student where ssex