目錄
表結構：
CREATE TABLE student(
sno VARCHAR(10) PRIMARY KEY, --學號
sname VARCHAR(20), --姓名
sage INT, --年齡
ssex VARCHAR(5) --性別
);
CREATE TABLE teacher(
tno VARCHAR(10) PRIMARY KEY, --教師號
tname VARCHAR(20) --姓名
);
CREATE TABLE course(
cno VARCHAR(10), --課程號
cname VARCHAR(20), --課程名稱
tno VARCHAR(20), --教師號
CONSTRAINT pk_course PRIMARY KEY (cno,tno)
);
CREATE TABLE sc(
sno VARCHAR(10), --學號
cno VARCHAR(10), --課程號
score DOUBLE, --成績
CONSTRAINT pk_sc PRIMARY KEY (sno,cno)
);
初始數據：
/*******初始化學生表的數據******/
insert into student values ('s001','張三',23,'男');
insert into student values ('s002','李四',23,'男');
insert into student values ('s003','吳鵬',25,'男');
insert into student values ('s004','琴沁',20,'女');
insert into student values ('s005','王麗',20,'女');
insert into student values ('s006','李波',21,'男');
insert into student values ('s007','劉玉',21,'男');
insert into student values ('s008','蕭蓉',21,'女');
insert into student values ('s009','陳蕭曉',23,'女');
insert into student values ('s010','陳美',22,'女');
commit;
/******************初始化教師表***********************/
insert into teacher values ('t001', '劉陽');
insert into teacher values ('t002', '諶燕');
insert into teacher values ('t003', '胡明星');
commit;
/***************初始化課程表****************************/
insert into course values ('c001','J2SE','t002');
insert into course values ('c002','Java Web','t002');
insert into course values ('c003','SSH','t001');
insert into course values ('c004','Oracle','t001');
insert into course values ('c005','SQL SERVER 2005','t003');
insert into course values ('c006','C#','t003');
insert into course values ('c007','JavaScript','t002');
insert into course values ('c008','DIV+CSS','t001');
insert into course values ('c009','PHP','t003');
insert into course values ('c010','EJB3.0','t002');
commit;
/***************初始化成績表***********************/
insert into sc values ('s001','c001',78.9);
insert into sc values ('s002','c001',80.9);
insert into sc values ('s003','c001',81.9);
insert into sc values ('s004','c001',60.9);
insert into sc values ('s001','c002',82.9);
insert into sc values ('s002','c002',72.9);
insert into sc values ('s003','c002',81.9);
insert into sc values ('s001','c003','59');
commit;
以下練習中的數據是根據初始化到數據庫中的數據來寫的SQL 語句，請大家務必注意。
需求：
-- 1、查詢“c001”課程比“c002”課程成績高的所有學生的學號；
-- 2、查詢平均成績大於60 分的同學的學號和平均成績；
-- 3、查詢所有同學的學號、姓名、選課數、總成績；
-- 4、查詢姓“劉”的老師的個數；
-- 5、查詢沒學過“諶燕”老師課的同學的學號、姓名；
-- 6、查詢學過“c001”並且也學過編號“c002”課程的同學的學號、姓名
-- 7、查詢學過“諶燕”老師所教的課的同學的學號、姓名；
-- 8、查詢課程編號“c002”的成績比課程編號“c001”課程低的所有同學的學號、姓名；
-- 9、查詢所有課程成績小於60 分的同學的學號、姓名；
-- 10、查詢沒有學全所有課的同學的學號、姓名；
-- 11、查詢至少有一門課與學號爲“s001”的同學所學相同的同學的學號和姓名；
-- 12、查詢至少學過學號爲“s001”同學所有一門課的其他同學學號和姓名；
-- 13、把“SC”表中“諶燕”老師教的課的成績都更改爲此課程的平均成績；
-- 14、查詢和“s001”號的同學學習的課程完全相同的其他同學學號和姓名；
-- 15、刪除學習“諶燕”老師課的SC 表記錄；
-- 16、向SC 表中插入一些記錄，這些記錄要求符合以下條件：沒有上過編號“c002”課程的同學學號、“c002”號課的平均成績；
-- 17、查詢各科成績最高和最低的分：以如下形式顯示：課程ID，最高分，最低分
-- 18、按各科平均成績從低到高和及格率的百分數從高到低順序
-- 19、查詢不同老師所教不同課程平均分從高到低顯示
-- 20、統計列印各科成績,各分數段人數:課程ID,課程名稱,[100-85],[85-70],[70-60],[ <60]
-- 21、查詢每門課程被選修的學生數
-- 22、查詢出只選修了一門課程的全部學生的學號和姓名
-- 23、查詢男生、女生人數
-- 24、查詢姓“張”的學生名單
-- 25、查詢同名同性學生名單，並統計同名人數
-- 26、查詢每門課程的平均成績，結果按平均成績升序排列，平均成績相同時，按課程號降序排列
-- 27、查詢平均成績大於85 的所有學生的學號、姓名和平均成績
-- 28、查詢課程名稱爲“數據庫”，且分數低於60 的學生姓名和分數
-- 29、查詢所有學生的選課情況；
-- 30、查詢任何一門課程成績在70 分以上的姓名、課程名稱和分數；
-- 31、查詢不及格的課程，並按課程號從大到小排列
-- 32、查詢課程編號爲c001 且課程成績在80 分以上的學生的學號和姓名；
-- 33、求選了課程的學生人數
-- 34、查詢選修“諶燕”老師所授課程的學生中，成績最高的學生姓名及其成績
-- 35、查詢各個課程及相應的選修人數
-- 36、查詢不同課程成績相同的學生的學號、課程號、學生成績
-- 37、統計每門課程的學生選修人數（超過10 人的課程才統計）。要求輸出課程號和選修人數，查詢結果按人數降序排列，若人數相同，按課程號升序排列
-- 38、檢索至少選修兩門課程的學生學號
-- 39、查詢全部學生都選修的課程的課程號和課程名
-- 40、查詢沒學過“諶燕”老師講授的任一門課程的學生姓名
-- 41、查詢兩門以上不及格課程的同學的學號及其平均成績
-- 42、檢索“c004”課程分數小於60，按分數降序排列的同學學號
-- 43、刪除“s002”同學的“c001”課程的成績
參考答案:
1.
*********************************
select a.* from
(select * from sc a where a.cno='c001') a,
(select * from sc b where b.cno='c002') b
where a.sno=b.sno and a.score > b.score;
*********************************
select * from sc a
where a.cno='c001'
and exists(select * from sc b where b.cno='c002' and a.score>b.score
and a.sno = b.sno)
*********************************
2.
*********************************
select sno,avg(score) from sc group by sno having avg(score)>60;
*********************************
3.
*********************************
select a.*,s.sname from (select sno,sum(score),count(cno) from sc group by sno) a ,student s where a.sno=s.sno
*********************************
4.
*********************************
select count(*) from teacher where tname like '劉%';
*********************************
5.
*********************************
select a.sno,a.sname from student a
where a.sno
not in
(select distinct s.sno
from sc s,
(select c.*
from course c ,
(select tno
from teacher t
where tname='諶燕')t
where c.tno=t.tno) b
where s.cno = b.cno )
*********************************
select * from student st where st.sno not in
(select distinct sno from sc s join course c on s.cno=c.cno
join teacher t on c.tno=t.tno where tname='諶燕')
*********************************
6.
*********************************
select st.* from sc a
join sc b on a.sno=b.sno
join student st
on st.sno=a.sno
where a.cno='c001' and b.cno='c002' and st.sno=a.sno;
*********************************
7.
*********************************
select st.* from student st join sc s on st.sno=s.sno
join course c on s.cno=c.cno
join teacher t on c.tno=t.tno
where t.tname='諶燕'
*********************************
8.
*********************************
select * from student st
join sc a on st.sno=a.sno
join sc b on st.sno=b.sno
where a.cno='c002' and b.cno='c001' and a.score < b.score
*********************************
9.
*********************************
select st.*,s.score from student st
join sc s on st.sno=s.sno
join course c on s.cno=c.cno
where s.score <60
*********************************
10.
*********************************
select stu.sno,stu.sname,count(sc.cno) from student stu
left join sc on stu.sno=sc.sno
group by stu.sno,stu.sname
having count(sc.cno)<(select count(distinct cno)from course)
*********************************
11.
*********************************
select st.* from student st,
(select distinct a.sno from
(select * from sc) a,
(select * from sc where sc.sno='s001') b
where a.cno=b.cno) h
where st.sno=h.sno and st.sno<>'s001'
*********************************
12.
*********************************
select * from sc
left join student st
on st.sno=sc.sno
where sc.sno<>'s001'
and sc.cno in
(select cno from sc
where sno='s001')
*********************************
13.
*********************************
update sc c set score=(select avg(c.score) from course a,teacher b
where a.tno=b.tno
and b.tname='諶燕'
and a.cno=c.cno
group by c.cno)
where cno in(
select cno from course a,teacher b
where a.tno=b.tno
and b.tname='諶燕')
*********************************
14.
*********************************
select* from sc where sno<>'s001'
minus
(
select* from sc
minus
select * from sc where sno='s001'
)
*********************************
15.
*********************************
delete from sc
where sc.cno in
(
select cno from course c
left join teacher t on c.tno=t.tno
where t.tname='諶燕'
)
*********************************
16.
*********************************
insert into sc (sno,cno,score)
select distinct st.sno,sc.cno,(select avg(score)from sc where cno='c002')
from student st,sc
where not exists
(select * from sc where cno='c002' and sc.sno=st.sno) and sc.cno='c002';
*********************************
17.
*********************************
select cno ,max(score),min(score) from sc group by cno;
*********************************
18.
*********************************
select cno,avg(score),sum(case when score>=60 then 1 else 0 end)/count(*)
as 及格率
from sc group by cno
order by avg(score) , 及格率desc
*********************************
19.
*********************************
select max(t.tno),max(t.tname),max(c.cno),max(c.cname),c.cno,avg(score) from sc , course c,teacher t
where sc.cno=c.cno and c.tno=t.tno
group by c.cno
order by avg(score) desc
*********************************
20.
*********************************
select sc.cno,c.cname,
sum(case when score between 85 and 100 then 1 else 0 end) AS "[100-85]",
sum(case when score between 70 and 85 then 1 else 0 end) AS "[85-70]",
sum(case when score between 60 and 70 then 1 else 0 end) AS "[70-60]",
sum(case when score <60 then 1 else 0 end) AS "[<60]"
from sc, course c
where sc.cno=c.cno
group by sc.cno ,c.cname;
*********************************
21.
*********************************
select cno,count(sno)from sc group by cno;
*********************************
22.
*********************************
select sc.sno,st.sname,count(cno) from student st
left join sc
on sc.sno=st.sno
group by st.sname,sc.sno having count(cno)=1;
*********************************
23.
*********************************
select ssex,count(*)from student group by ssex;
*********************************
24.
*********************************
select * from student where sname like '張%';
*********************************
25.
*********************************
select sname,count(*)from student group by sname having count(*)>1;
*********************************
26.
*********************************
select cno,avg(score) from sc group by cno order by avg(score)asc,cno desc;
*********************************
27.
*********************************
select st.sno,st.sname,avg(score) from student st
left join sc
on sc.sno=st.sno
group by st.sno,st.sname having avg(score)>85;
*********************************
28.
*********************************
select sname,score from student st,sc,course c
where st.sno=sc.sno and sc.cno=c.cno and c.cname='Oracle' and sc.score<60
*********************************
29.
*********************************
select st.sno,st.sname,c.cname from student st,sc,course c
where sc.sno=st.sno and sc.cno=c.cno;
*********************************
30.
*********************************
select st.sname,c.cname,sc.score from student st,sc,course c
where sc.sno=st.sno and sc.cno=c.cno and sc.score>70
*********************************
31.
*********************************
select sc.sno,c.cname,sc.score from sc,course c
where sc.cno=c.cno and sc.score<60 order by sc.cno desc;
*********************************
32.
*********************************
select st.sno,st.sname,sc.score from sc,student st
where sc.sno=st.sno and cno='c001' and score>80;
*********************************
33.
*********************************
select count(distinct sno) from sc;
*********************************
34.
*********************************
select st.sname,score from student st,sc ,course c,teacher t
where
st.sno=sc.sno and sc.cno=c.cno and c.tno=t.tno
and t.tname='諶燕' and sc.score=
(select max(score)from sc where sc.cno=c.cno)
*********************************
35.
*********************************
select cno,count(sno) from sc group by cno;
*********************************
36.
*********************************
select a.* from sc a ,sc b where a.score=b.score and a.cno<>b.cno
*********************************
37.
*********************************
select cno,count(sno) from sc group by cno
having count(sno)>10
order by count(sno) desc,cno asc;
*********************************
38.
*********************************
select sno from sc group by sno having count(cno)>1;
||
select sno from sc group by sno having count(sno)>1;
*********************************
39.
*********************************
select distinct(c.cno),c.cname from course c ,sc
where sc.cno=c.cno
||
select cno,cname from course c
where c.cno in
(select cno from sc group by cno)
*********************************
40.
*********************************
select st.sname from student st
where st.sno not in
(select distinct sc.sno from sc,course c,teacher t
where sc.cno=c.cno and c.tno=t.tno and t.tname='諶燕')
*********************************
41.
*********************************
select sno,avg(score)from sc
where sno in
(select sno from sc where sc.score<60
group by sno having count(sno)>1
) group by sno
*********************************
42.
*********************************
select sno from sc where cno='c004' and score<90 order by score desc;
*********************************
43.
*********************************
delete from sc where sno='s002' and cno='c001';
*********************************