SQL數(shù)據(jù)庫面試題及答案

1、Student(S#,Sname,Sage,Ssex) 學(xué)生表Ssex學(xué)生性別Course(C#,Cname,T#) 課程表 教師編號SC(S#,C#,score)成績表績Teacher(T#,Tname) 教師表S#:學(xué)號；Sname :學(xué)生姓名；Sage：學(xué)生年齡;C#課程編號；Cname：課程名字；T#：S#:學(xué)號；C#課程編號；score :成T#：教師編號；Tn ame :教師名字問題：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

2、,(select s#,scorefrom SC where C#='002') bwhere 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 scgroup 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

3、.S#=SC.S#group by Student.S#,Sname4、查詢姓“李”的老師的個數(shù)；select count(distinct(Tname)from Teacherwhere 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；select Student.S#,Student.Snamefrom Studentwhere S# not in (select distinct( SC.S#) from SC,Course,Teacherwhere SC.C#=Course.C# and Teacher.T#=Course.T# and

4、 Teacher.T name 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#,Snamefrom Studentwher

5、e 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=H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 (se

6、lect Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#='002') score2from 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#,Snamefrom Studentwhere S# not in (select Student.S# f

7、rom 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.Snamefrom Student,SCwhere 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 wher

8、e 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,SCwhere 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_

9、2.score)from SC SC_2where SC_2.C#=SC.C# ) from Course,Teacher where Course.C#=SC.C# andCourse.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 S

10、C where S#='1002');15、 刪除學(xué)習(xí)“葉平”老師課的SC表記錄；Delect SCfrom course ,Teacherwhere 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)from SC where C#='002') from Student w

11、here 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# a學(xué)生 ID(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004')數(shù)據(jù)庫(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001)企業(yè)管理,(SELECT

12、 score FROM SC WHERE SC.S#=t.S# AND C#='006')英語，COUNT(*) AS 有效課程數(shù) ， AVG(t.score) AS 平均成績FROM SC AS tGROUP 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# A課程 ID,L.score AS 最高分，R.score AS 最低分FROM SC L ,SC AS RWHERE L.C# = R.C# andL.score = (SELECT MAX(IL.score) FRO

13、M SC AS IL,Student AS IM WHERE L.C# = IL.C# and IM.S#=IL.S#GROUP BY IL.C#)ANDR.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數(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 isn ull(score,0)>=60

14、 THEN 1 ELSE 0 END)/COUNT(*) AS 及格 百分數(shù)FROM SC T,Coursewhere t.C#=course.C#GROUP BY t.C#ORDERBY 100 * SUM(CASEWHEN isnull(score,0)>=60 THEN 1 ELSE0 END)/COUNT(*) DESC20、 查詢?nèi)缦抡n程平均成績和及格率的百分數(shù)(用"1 行"顯示): 企業(yè)管理( 0 0 1 )，馬克思( 0 02)， OO&UML ( 003)，數(shù)據(jù)庫( 004)SELECTSUM(CASE WHEN C# ='001

15、9; THEN score ELSE0 END)/SUM(CASEC# WHEN '001' THEN 1 ELSE 0 END) A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) A企業(yè)管理及格百分數(shù),SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '

16、;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) A馬克思及格百分數(shù),SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/SUM(CASE C# WHEN '003' THEN 1 ELSE 0 END) AS UM平 均分,100 * S

17、UM(CASE WHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '003' THEN 1 ELSE 0 END) AS UM及格百分數(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 >

18、;= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '004' THEN 1 ELSE 0 END) A數(shù)據(jù)庫及格百分數(shù)FROM SC21 、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FROM SC AS T,Course AS C ,Teacher AS Zwhere T.C#=C.C# and C.T#=Z.T#GROUP BY C.C#ORDER

19、 BY AVG(Score) DESC22、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 DISTINCT top 3SC.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,

20、0) + ISNULL(T4.score,0) as 總 分FROM Student,SC LEFT JOIN SC AS T1ON SC.S# = T1.S# AND T1.C# = '001'LEFT JOIN SC AS T2ON SC.S# = T2.S# AND T2.C# = '002'LEFT JOIN SC AS T3ON SC.S# = T3.S# AND T3.C# = '003'LEFT JOIN SC AS T4ON SC.S# = T4.S# AND T4.C# = '004'WHERE student.

21、S#=SC.S# andISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)NOT IN(SELECTDISTINCTTOP 15 WITH TIESISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) FROM scLEFT JOIN sc AS T1ON sc.S# = T1.S# AND T1.C# = 'k1'LEFT JOIN sc AS T2ON s

22、c.S# = T2.S# AND T2.C# = 'k2'LEFT JOIN sc AS T3ON sc.S# = T3.S# AND T3.C# = 'k3'LEFT JOIN sc AS T4ON sc.S# = T4.S# AND T4.C# = 'k4'ORDER BY ISNULL(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，各分數(shù)段人數(shù)：課程ID,課程名稱，100-85,85-70,70-60,

23、 <60SELECT SC.C# a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

24、 -FROM SC,Coursewhere SC.C#=Course.C#GROUP BY SC.C#,Cname;24、查詢學(xué)生平均成績及其名次SELECT 1+(SELECT COUNT( distin平均成績)FROM (SELECT S#,AVG(score) A平 均成績FROM SCGROUP BY S#) AS T1WHERE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 SCGROUP BY S#) AS T2ORDER BY平均成績desc;25、 查詢各科成績前三名的記錄:(不

25、考慮成績并列情況 )SELECT tl.S# a學(xué)生 ID,t1.C# as 課程 ID,Score as 分數(shù)FROM SC t1WHERE score IN (SELECT TOP 3 scoreFROM SCWHERE t1.C#= C#ORDER BY score DESC)ORDER BY tl.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select SC.S#,Stude nt.S name,cou nt(C#) AS 選課數(shù)from SC ,Student

26、where SC.S#=Student.S# group by SC.S# ,Student.Sname having count(C#)=1;28、查詢男生、女生人數(shù)Select coun t(Ssex) as 男生人數(shù) from Stude nt group by Ssex havi ng 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 Sn ame FROM Stude nt WHERE Sn ame liK&

27、#39;%'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 Student group 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 agefrom studentwhere 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

28、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,SCwhere 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” ，且分數(shù)低于 60 的學(xué)生姓名和分數(shù)Select Sname,isnull(score,0)from

29、 Student,SC,Coursewhere 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,CnameFROM SC,Student,Coursewhere 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、課程名稱和分數(shù)；SELECT distinct student.S#,student.Sname,SC.C#,S

30、C.scoreFROM student,ScWHERE 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 andC#='003'39、求選了課程的學(xué)生人數(shù)select co

31、unt(*) 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,scorefrom Student,SC,Course C,Teacherwhere Student.S#=SC.S# and SC.C#=C.C# and C.T#=Teacher.T# and Teacher.Tnam葉平'andSC.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 wh