最近在學(xué)習(xí)SQL嘛,所以各個地方找題目來練手,畢竟現(xiàn)在能離得開數(shù)據(jù)庫么?
Student(S#,Sname,Sage,Ssex) 學(xué)生表
Course(C#,Cname,T#) 課程表
SC(S#,C#,score) 成績表
Teacher(T#,Tname) 教師表

問題：
1、查詢“001”課程比“002”課程成績高的所有學(xué)生的學(xué)號；

select a.S# from (select s#,score from SC where C#='001') a,(select s#,score from SC where C#='002') b where a.score>b.score and a.s#=b.s#; 

2、查詢平均成績大于60分的同學(xué)的學(xué)號和平均成績；

 select S#,avg(score) from sc group by S# having avg(score) >60; 

3、查詢所有同學(xué)的學(xué)號、姓名、選課數(shù)、總成績；

select Student.S#,Student.Sname,count(SC.C#),sum(score) from Student left Outer join SC on Student.S#=SC.S# group by Student.S#,Sname 

4、查詢姓“李”的老師的個數(shù)；

select count(distinct(Tname)) from Teacher where Tname like '李%'; 

5、查詢沒學(xué)過“葉平”老師課的同學(xué)的學(xué)號、姓名；

Student.S#,Student.Sname from Student  where S# not in (select distinct( SC.S#) from SC,Course,Teacher where  SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname='葉平'); 

6、查詢學(xué)過“001”并且也學(xué)過編號“002”課程的同學(xué)的學(xué)號、姓名；

 select Student.S#,Student.Sname from Student,SC where Student.S#=SC.S# and SC.C#='001'and exists( Select * from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#='002'); 

7、查詢學(xué)過“葉平”老師所教的所有課的同學(xué)的學(xué)號、姓名；

select S#,Sname from Student where S# in (select S# from SC ,Course ,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname='葉平' group by S# having count(SC.C#)=(select count(C#) from
Course,Teacher  where Teacher.T#=Course.T# 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(xué)的學(xué)號、姓名；

Select S#,Sname from (select Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#='002') score2 from Student,SC where Student.S#=SC.S# and C#='001') S_2 where score2 <score; 

9、查詢所有課程成績小于60分的同學(xué)的學(xué)號、姓名；

select S#,Sname from Student where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60); 

10、查詢沒有學(xué)全所有課的同學(xué)的學(xué)號、姓名；

select Student.S#,Student.Sname from Student,SC where Student.S#=SC.S# group by  Student.S#,Student.Sname having count(C#) <(select count(C#) from Course); 

11、查詢至少有一門課與學(xué)號為“1001”的同學(xué)所學(xué)相同的同學(xué)的學(xué)號和姓名；

select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where S#='1001'; 

12、查詢至少學(xué)過學(xué)號為“001”同學(xué)所有一門課的其他同學(xué)學(xué)號和姓名；

select distinct SC.S#,Sname from Student,SC where Student.S#=SC.S# and C# in (select C# from SC where S#='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.C#=SC.C# ) from Course,Teacher where Course.C#=SC.C# and Course.T#=Teacher.T# and Teacher.Tname='葉平'); 

14、查詢和“1002”號的同學(xué)學(xué)習(xí)的課程完全相同的其他同學(xué)學(xué)號和姓名；

    select S# from SC where C# in (select C# from SC where S#='1002') group by
S# having count(*)=(select count(*) from SC where S#='1002');

15、刪除學(xué)習(xí)“葉平”老師課的SC表記錄；

Delect SC from course ,Teacher  where Course.C#=SC.C# and Course.T#= Teacher.T# 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(xué)學(xué)號、2、
號課的平均成績；

INSERT SC SELECT
S #,'002',(Select avg(score)FROMSC 
WHEREC #='002') from Student where S# not in (Select S# from SC where C#='002');

17、按平均成績從高到低顯示所有學(xué)生的“數(shù)據(jù)庫”、“企業(yè)管理”、“英語”三門的課程成績，按如下形式顯示： 學(xué)生ID,數(shù)據(jù)庫,企業(yè)管理,英語,有效課程數(shù),有效平均分

    SELECT S# as 學(xué)生ID ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 數(shù)據(jù)庫
,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企業(yè)管理 ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英語 ,COUNT(*) AS 有效課程數(shù), AVG(t.score) AS 平均成績 FROM SC AS t GROUP BY S# ORDER BY avg(t.score)  

18、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 L.C# As 課程ID,L.score AS 最高分,R.score AS 最低分 FROM SC L ,SC AS R WHERE L.C# = R.C# and L.score = (SELECT MAX(IL.score) FROM SC AS IL,Student AS IM WHERE L.C# = IL.C# and IM.S#=IL.S# GROUP BY IL.C#) AND R.Score
= (SELECT MIN(IR.score) FROM SC AS IR WHERE R.C# = IR.C# GROUP BY IR.C# ); 

19、按各科平均成績從低到高和及格率的百分?jǐn)?shù)從高到低順序

    SELECT t.C# 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?jǐn)?shù) FROM SC T,Course where t.C#=course.C# GROUP BY t.C# ORDER BY 100 * SUM(CASE WHEN  isnull(score,0)>=60 THEN 1 ELSE
0 END)/COUNT(*) DESC 

20、查詢?nèi)缦抡n程平均成績和及格率的百分?jǐn)?shù)(用"1行"顯示): 企業(yè)管理（001），馬克思（002），OO&UML （003），數(shù)據(jù)庫（004）

    SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1 ELSE 0 END) AS 企業(yè)管理平均分 ,100 * SUM(CASE WHEN C# = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '001' THEN 1 ELSE 0 END
) AS 企業(yè)管理及格百分?jǐn)?shù) ,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 馬克思平均分 ,100 * SUM(CASE WHEN C# = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '002' THEN 1 ELSE 0 END) AS 馬克思及格百分?jǐn)?shù) ,SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/
SUM(CASE C# WHEN '003' THEN 1 ELSE 0 END) AS UML平均分 ,100 * SUM(CASE WHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '003' THEN 1 ELSE 0 END) AS UML及格百分?jǐn)?shù) ,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1 ELSE 0 END) AS 數(shù)據(jù)庫平均分 ,100
* SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '004' THEN 1 ELSE 0 END) AS 數(shù)據(jù)庫及格百分?jǐn)?shù) FROM SC 

21、查詢不同老師所教不同課程平均分從高到低顯示

SELECTmax(Z.T #) AS 教師ID,MAX(Z.Tname) AS 教師姓名,C.C# AS 課程ＩＤ,MAX(C.Cname) AS 課程名稱,AVG(Score) AS 平均成績FROMSC AS T,Course AS C,Teacher AS Z 
WHERET.C #=C.C# and C.T#=Z.T#GROUP BYC.C #ORDER BYAVG( Score ) DESC

22、查詢?nèi)缦抡n程成績第 3 名到第 6 名的學(xué)生成績單：企業(yè)管理（001），馬克思（002），UML （003），數(shù)據(jù)庫（004）
[學(xué)生ID],[學(xué)生姓名],企業(yè)管理,馬克思,UML,數(shù)據(jù)庫,平均成績

SELECT DISTINCTtop 3 SC.S # As 學(xué)生學(xué)號,Student.Sname AS 學(xué)生姓名,T1.score AS 企業(yè)管理,T2.score AS 馬克思,T3.score AS UML,T4.score AS 數(shù)據(jù)庫,ISNULL( T1.score, 0 ) + ISNULL( T2.score, 0 ) + ISNULL( T3.score, 0 ) + ISNULL( T4.score, 0 ) AS 總分 
FROMStudent,SCLEFT JOIN SC AS T1 ON SC.S # = T1.S# AND T1.C# = '001'LEFT JOIN SC AS T2 ON SC.S # = T2.S# AND T2.C# = '002'LEFT JOIN SC AS T3 ON SC.S # =T3.S# AND T3.C# = '003'LEFT JOIN SC AS T4 ON SC.S # = T4.S# AND T4.C# = '004'WHEREstudent.S #=SC.S# andISNULL( T1.score, 0 ) + ISNULL( T2.score, 0 ) + ISNULL( T3.score, 0 ) + ISNULL( T4.score, 0 ) NOT IN (
SELECT DISTINCTTOP 15 WITH TIES ISNULL( T1.score, 0 ) + ISNULL( T2.score, 0 ) + ISNULL( T3.score, 0 ) + ISNULL( T4.score, 0 ) FROMscLEFT JOIN sc AS T1 ON sc.S # = T1.S# AND T1.C#= 'k1'LEFT JOIN sc AS T2 ON sc.S # = T2.S# AND T2.C# = 'k2'LEFT JOIN sc AS T3 ON sc.S # = T3.S# AND T3.C# = 'k3'LEFT JOIN sc AS T4 ON sc.S # = T4.S# AND T4.C# = 'k4'ORDER BYISNULL( T1.score, 0 ) + ISNULL( T2.score, 0 ) + ISNULL( T3.score, 0 ) + ISNULL( T4.score, 0 ) DESC 
);

23、統(tǒng)計列印各科成績,各分?jǐn)?shù)段人數(shù):課程ID,課程名稱,[100-85],[85-70],[70-60],[ <60]

SELECTSC.C # as 課程ID, CnameAS 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 -] 
FROMSC,Coursewhere SC.C #=Course.C#GROUP BYSC.C #,Cname;

24、查詢學(xué)生平均成績及其名次

SELECT1+ ( SELECT COUNT( DISTINCT 平均成績 ) FROM ( SELECT S #,AVG(score) AS 平均成績FROM SC GROUP BY S #) AS T1 WHERE 平均成績 > T2.平均成績 ) AS 名次,S # as 學(xué)生學(xué)號,平均成績FROM( SELECT S #,AVG(score) 平均成績FROM SC GROUP BY S #
) AS T2 
ORDER BY
平均成績 DESC;

25、查詢各科成績前三名的記錄:(不考慮成績并列情況)

SELECTt1.S # as 學(xué)生ID,t1.C# as 課程ID,Score as 分?jǐn)?shù)FROMSC t1 
WHEREscore IN ( SELECT TOP 3 score FROM SC WHERE t1.C #= C#     ORDER BY score DESC) 
ORDER BY
t1.C #; 

26、查詢每門課程被選修的學(xué)生數(shù)

select c#,count(S#) from sc group by C#; 

27、查詢出只選修了一門課程的全部學(xué)生的學(xué)號和姓名

SELECTSC.S #,Student.Sname,count(C#) AS 選課數(shù)FROMSC,Student 
WHERESC.S #=Student.S# group by SC.S# ,Student.Sname having count(C#)=1;

28、查詢男生、女生人數(shù)

Select count(Ssex) as 男生人數(shù) from Student group by Ssex having Ssex='男'; 
Select count(Ssex) as 女生人數(shù) from Student group by Ssex having Ssex='女'；

29、查詢姓“張”的學(xué)生名單

  SELECT Sname FROM Student WHERE Sname like '張%'; 

30、查詢同名同性學(xué)生名單，并統(tǒng)計同名人數(shù)

 select Sname,count(*) from Studentgroup by Sname having  count(*)>1;;

31、1981年出生的學(xué)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'; 

32、查詢每門課程的平均成績，結(jié)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 C#,Avg(score) from SC group by C# order by Avg(score),C# DESC ; 

33、查詢平均成績大于85的所有學(xué)生的學(xué)號、姓名和平均成績

select Sname,SC.S# ,avg(score) 
from Student,SC 
where Student.S#=SC.S# group by SC.S#,Sname having    avg(score)>85; 

34、查詢課程名稱為“數(shù)據(jù)庫”，且分?jǐn)?shù)低于60的學(xué)生姓名和分?jǐn)?shù)

Select Sname,isnull(score,0) 
from Student,SC,Course 
where SC.S#=Student.S# and SC.C#=Course.C#and  Course.Cname='數(shù)據(jù)庫'and score <60;

35、查詢所有學(xué)生的選課情況；

SELECT SC.S#,SC.C#,Sname,Cname 
FROM SC,Student,Course 
where SC.S#=Student.S# and SC.C#=Course.C# ; 

36、查詢?nèi)魏我婚T課程成績在70分以上的姓名、課程名稱和分?jǐn)?shù)；

 SELECT  distinct student.S#,student.Sname,SC.C#,SC.score FROM student,Sc WHERE SC.score>=70 AND SC.S#=student.S#; 

37、查詢不及格的課程，并按課程號從大到小排列

select c# from sc where scor e <60 order by C# ; 

38、查詢課程編號為003且課程成績在80分以上的學(xué)生的學(xué)號和姓名；

select SC.S#,Student.Sname from SC,Student where SC.S#=Student.S# and Score>80 and C#='003'; 

39、求選了課程的學(xué)生人數(shù)

select count(*) from sc; 

40、查詢選修“葉平”老師所授課程的學(xué)生中，成績最高的學(xué)生姓名及其成績

    select Student.Sname,score from Student,SC,Course C,Teacher where Student.S#=SC.S# and SC.C#=C.C# and
C.T#=Teacher.T# and Teacher.Tname='葉平' and SC.score=(select max(score)from SC where C#=C.C# ); 

41、查詢各個課程及相應(yīng)的選修人數(shù)

select count(*) from sc group by C#; 

42、查詢不同課程成績相同的學(xué)生的學(xué)號、課程號、學(xué)生成績

select distinct  A.S#,B.score from SC A  ,SC B where A.Score=B.Score and A.C# <>B.C# ; 

43、查詢每門功成績最好的前兩名

 SELECT t1.S# as 學(xué)生ID,t1.C# as 課程ID,Score as 分?jǐn)?shù) FROM SC t1 WHERE score IN (SELECT TOP 2 score FROM SC WHERE t1.C#= C# ORDER BY score DESC ) ORDER BY t1.C#; 

44、統(tǒng)計每門課程的學(xué)生選修人數(shù)（超過10人的課程才統(tǒng)計）。要求輸出課程號和選修人數(shù)，查詢結(jié)果按人數(shù)降序排列，查詢結(jié)果按人數(shù)降序排列，若人數(shù)相同，按課程號升序排列

 select  C# as 課程號,count(*) as 人數(shù)from  sc  group  by  C# order  by  count(*) desc,c# 

45、檢索至少選修兩門課程的學(xué)生學(xué)號

 select  S#  from  sc  group  by  s# having  count(*)  >  =  2 

46、查詢?nèi)繉W(xué)生都選修的課程的課程號和課程名

select  C#,Cname  
from  Course  
where  C#  in  (select  c#  from  sc group  by  c#) 

47、查詢沒學(xué)過“葉平”老師講授的任一門課程的學(xué)生姓名

 select Sname from Student where S# not in (select S# from Course,Teacher,SC where Course.T#=Teacher.T# and SC.C#=course.C# and Tname='葉平'); 

48、查詢兩門以上不及格課程的同學(xué)的學(xué)號及其平均成績

    select S#,avg(isnull(score,0)) from SC where S# in (select S# from SC where
score <60 group by S# having count(*)>2)group by S#; 

49、檢索“004”課程分?jǐn)?shù)小于60，按分?jǐn)?shù)降序排列的同學(xué)學(xué)號

 select S# from SC where C#='004'and score <60 order by score desc; 

50、刪除“002”同學(xué)的“001”課程的成績

delete from Sc where S#='001'and C#='001';