SQL查詢題目
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SQL查詢題目
條件：
Student(Sno,Sname,Sage,Ssex) 學生表
Course(Cno,Cname,Tno) 課程表
SC(Sno,Cno,score) 成績表（選課表）
Teacher(Tno,Tname) 教師表
問題：
1、查詢“001”課程比“002”課程成績高的所有學生的學號；
select a.sno from (select sno,score from SC where cno='001') a,(select sno,score
from SC where cno='002') b
where a.score>b.score and a.sno=b.sno;
2、查詢平均成績大於60分的同學的學號和平均成績；
select SNO,avg(score) from sc group by SNO having avg(score) >60;
3、查詢所有同學的學號、姓名、選課數、總成績；
select Student.SNO,Student.Sname,count(SC.CNO),sum(score)
from Student left Outer join SC on Student.SNO=SC.SNO
group by Student.SNO,Sname
4、查詢姓“李”的老師的個數；
select count(distinct(Tname))
from Teacher where Tname like '李%';
5、查詢沒學過“葉平”老師課的同學的學號、姓名；
select Student.SNO,Student.Sname from Student
where SNO not in (select distinct(SC.SNO) from SC,Course,Teacher where SC.CNO=Course.CNO and Teacher.Tno=Course.Tno and Teacher.Tname='葉平');
6、查詢學過“001”並且也學過編號“002”課程的同學的學號、姓名；
select Student.SNO,Student.Sname from Student,SC where Student.SNO=SC.SNO and SC.CNO='001'and exists( Select * from SC as SC_2 where SC_2.SNO=SC.SNO and SC_2.CNO='002');
7、查詢學過“葉平”老師所教的所有課的同學的學號、姓名；
select SNO,Sname
from Student
where SNO in (select SNO from SC ,Course ,Teacher where SC.CNO=Course.CNO and Teacher.TNO=Course.TNO and Teacher.Tname='葉平' group by SNO having count(SC.CNO)=(select count(CNO) from Course,Teacher where Teacher.TNO=Course.TNO and Tname='葉平'));
8、查詢課程編號“002”的成績比課程編號“001”課程低的所有同學的學號、姓名；
Select SNO,Sname from (select Student.SNO,Student.Sname,score ,(select score from SC SC_2 where SC_2.SNO=Student.SNO and SC_2.CNO='002') score2
from Student,SC where Student.SNO=SC.SNO and CNO='001') S_2 where score2 <score;
9、查詢所有課程成績小於60分的同學的學號、姓名；
select SNO,Sname
from Student
where SNO not in (select Student.SNO from Student,SC where S.SNO=SC.SNO and score>60);
10、查詢沒有學全所有課的同學的學號、姓名；
select Student.SNO,Student.Sname
from Student,SC
where Student.SNO=SC.SNO group by Student.SNO,Student.Sname having count(CNO) <(select count(CNO) from Course);
11、查詢至少有一門課與學號為“1001”的同學所學相同的同學的學號和姓名；
select SNO,Sname from Student,SC where Student.SNO=SC.SNO and CNO in select CNO from SC where SNO='1001';
12、查詢至少學過學號為“001”同學所有一門課的其他同學學號和姓名；
select distinct SC.SNO,Sname
from Student,SC
where Student.SNO=SC.SNO and CNO in (select CNO from SC where SNO='001');
13、把“SC”表中“葉平”老師教的課的成績都更改為此課程的平均成績；
update SC set score=(select avg(SC_2.score)
from SC SC_2
where SC_2.CNO=SC.CNO) from Course,Teacher where Course.CNO=SC.CNO and Course.TNO=Teacher.TNO and Teacher.Tname='葉平');
14、查詢和“1002”號的同學學習的課程完全相同的其他同學學號和姓名；
select SNO from SC where CNO in (select CNO from SC where SNO='1002')
group by SNO having count(*)=(select count(*) from SC where SNO='1002');
15、刪除學習“葉平”老師課的SC表記錄；
DelectSC
from course ,Teacher
where Course.CNO=SC.CNO and Course.TNO= Teacher.TNO and Tname='葉平';
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“003”課程的同學學號、2號課的平均成績；
Insert SC select SNO,'002',(Select avg(score)
from SC where CNO='002') from Student where SNO not in (Select SNO from SC where CNO='002');
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
SELECT SNO as 學生ID
,(SELECT score FROM SC WHERE SC.SNO=t.SNO AND CNO='004') AS 數據庫
,(SELECT score FROM SC WHERE SC.SNO=t.SNO AND CNO='001') AS 企業管理
,(SELECT score FROM SC WHERE SC.SNO=t.SNO AND CNO='006') AS 英語
,COUNT(*) AS 有效課程數, AVG(t.score) AS 平均成績
FROM SC AS t
GROUP BY SNO
ORDER BY avg(t.score)
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
SELECT t.CNO AS 課程號,max(course.Cname)AS 課程名,isnull(AVG(score),0) AS 平均成績
,100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) AS 及格百分數
FROM SC T,Course
where t.CNO=course.CNO
GROUP BY t.CNO
ORDER BY 100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC
19、查詢不同老師所教不同課程平均分從高到低顯示
SELECT max(Z.TNO) AS 教師ID,MAX(Z.Tname) AS 教師姓名,C.CNO AS 課程ＩＤ,MAX(C.Cname) AS 課程名稱,AVG(Score) AS 平均成績
FROM SC AS T,Course AS C ,Teacher AS Z
where T.CNO=C.CNO and C.TNO=Z.TNO
GROUP BY C.CNO
ORDER BY AVG(Score) DESC
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]
SELECT SC.CNO as 課程ID, Cname as 課程名稱
,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
where SC.CNO=Course.CNO
GROUP BY SC.CNO,Cname;
21、查詢各科成績前三名的記錄:(不考慮成績並列情況)
SELECT t1.SNO as 學生ID,t1.CNO as 課程ID,Score as 分數
FROM SC t1
WHERE score IN (SELECT TOP 3 score
FROM SC
WHERE t1.CNO= CNO
ORDER BY score DESC
)
ORDER BY t1.CNO;
22、查詢每門課程被選修的學生數
select cno,count(SNO) from sc group by CNO;
23、查詢出只選修了一門課程的全部學生的學號和姓名
select SC.SNO,Student.Sname,count(CNO) AS 選課數
from SC ,Student
where SC.SNO=Student.SNO group by SC.SNO ,Student.Sname having count(CNO)=1;
24、查詢男生、女生人數
Select count(Ssex) as 男生人數from Student group by Ssex having Ssex='男';
Select count(Ssex) as 女生人數from Student group by Ssex having Ssex='女'；
25、查詢姓“張”的學生名單
SELECT Sname FROM Student WHERE Sname like '張%';
26、查詢同名同性學生名單，並統計同名人數
select Sname,count(*) from Student group by Sname having count(*)>1;
27、1981年出生的學生名單(注：Student表中Sage列的類型是datetime)
select Sname, CONVERT(char (11),DATEPART(year,Sage)) as age
from student
where CONVERT(char(11),DATEPART(year,Sage))='1981';
28、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
Select CNO,Avg(score) from SC group by CNO order by Avg(score),CNO DESC ;
29、查詢平均成績大於85的所有學生的學號、姓名和平均成績
select Sname,SC.SNO ,avg(score)
from Student,SC
where Student.SNO=SC.SNO group by SC.SNO,Sname having avg(score)>85;
30、查詢課程名稱為“數據庫”，且分數低於60的學生姓名和分數
Select Sname,isnull(score,0)
from Student,SC,Course
where SC.SNO=Student.SNO and SC.CNO=Course.CNO and Course.Cname='數據庫'and score <60;
31、查詢所有學生的選課情況；
SELECT SC.SNO,SC.CNO,Sname,Cname
FROM SC,Student,Course
where SC.SNO=Student.SNO and SC.CNO=Course.CNO ;
32、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；
SELECT distinct student.SNO,student.Sname,SC.CNO,SC.score
FROM student,Sc
WHERE SC.score>=70 AND SC.SNO=student.SNO;
33、查詢不及格的課程，並按課程號從大到小排列
select cno from sc where scor e <60 order by CNO ;
34、查詢課程編號為003且課程成績在80分以上的學生的學號和姓名；
select SC.SNO,Student.Sname from SC,Student where SC.SNO=Student.SNO and Score>80 and CNO='003';
35、求選了課程的學生人數
select count(*) from sc;
36、查詢選修“葉平”老師所授課程的學生中，成績最高的學生姓名及其成績
select Student.Sname,score
from Student,SC,Course C,Teacher
where Student.SNO=SC.SNO and SC.CNO=C.CNO and C.TNO=Teacher.TNO and Teacher.Tname='葉平' and SC.score=(select max(score)from SC where CNO=C.CNO );
37、查詢各個課程及相應的選修人數
select count(*) from sc group by CNO;
38、查詢不同課程成績相同的學生的學號、課程號、學生成績
select distinct A.SNO,B.score from SC A ,SC B where A.Score=B.Score and A.CNO <>B.CNO ;
39、查詢每門功成績最好的前兩名
SELECT t1.SNO as 學生ID,t1.CNO as 課程ID,Score as 分數
FROM SC t1
WHERE score IN (SELECT TOP 2 score
FROM SC
WHERE t1.CNO= CNO
ORDER BY score DESC
)
ORDER BY t1.CNO;
40、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，查詢結果按人數降序排列，若人數相同，按課程號升序排列
select CNO as 課程號,count(*) as 人數
from sc
group by CNO
order by count(*) desc,cno
41、檢索至少選修兩門課程的學生學號
select SNO
from sc
group by sno
having count(*) > = 2
42、查詢全部學生都選修的課程的課程號和課程名
select CNO,Cname
from Course
where CNO in (select cno from sc group by cno)
43、查詢沒學過“葉平”老師講授的任一門課程的學生姓名
select Sname from Student where SNO not in (select SNO from Course,Teacher,SC where Course.TNO=Teacher.TNO and SC.CNO=course.CNO and Tname='葉平');
44、查詢兩門以上不及格課程的同學的學號及其平均成績
select SNO,avg(isnull(score,0)) from SC where SNO in (select SNO from SC where score <60 group by SNO having count(*)>2)group by SNO;
45、檢索“004”課程分數小於60，按分數降序排列的同學學號
select SNO from SC where CNO='004'and score <60 order by score desc;
46、刪除“002”同學的“001”課程的成績
delete from Sc where SNO='001'and CNO='001';