資料庫習題及答案

weixin_42568854發表於2019-01-17
資料庫

SQL資料庫面試題以及答案1
轉載出處：https://www.cnblogs.com/rrxc/p/3994389.html

Student(stuId,stuName,stuAge,stuSex) 學生表

stuId：學號；stuName：學生姓名；stuAge：學生年齡；stuSex：學生性別

Course(courseId,courseName,teacherId) 課程表

courseId,課程編號；courseName：課程名字；teacherId：教師編號

Scores(stuId,courseId,score) 成績表

stuId：學號；courseId,課程編號；score：成績

Teacher(teacherId,teacherName) 教師表

teacherId：教師編號； teacherName：教師名字

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.stuId from (select stuId,score from Scores where courseId=‘001’) a,(select stuId,score

from Scores where courseId=‘002’) b

where a.score>b.score and a.stuId=b.stuId;

2、查詢平均成績大於60分的同學的學號和平均成績；

select stuId,avg(score)

from Scores

group by stuId having avg(score) >60;

3、查詢所有同學的學號、姓名、選課數、總成績；

select Student.stuId,Student.stuName,count(Scores.courseId),sum(score)

from Student left Outer join Scores on Student.stuId=Scores.stuId

group by Student.stuId,stuName

4、查詢姓“李”的老師的個數；

select count(distinct(teacherName))

from Teacher

where teacherName like ‘李%’;

5、查詢沒學過“葉平”老師課的同學的學號、姓名；

select Student.stuId,Student.stuName

from Student 

where stuId not in (select distinct( Scores.stuId) from Scores,Course,Teacher where  Scores.courseId=Course.courseId and Teacher.teacherId=Course.teacherId and Teacher.teacherName='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.stuId,Student.stuName from Student,Scores where Student.stuId=Scores.stuId and Scores.courseId='001'and exists( Select * from Scores as Scores_2 where Scores_2.stuId=Scores.stuId and Scores_2.courseId='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 stuId,stuName

  from Student

  where stuId in (select stuId from Scores ,Course ,Teacher where Scores.courseId=Course.courseId and Teacher.teacherId=Course.teacherId and Teacher.teacherName='葉平' group by stuId having count(Scores.courseId)=(select count(courseId) from Course,Teacher  where Teacher.teacherId=Course.teacherId and teacherName='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 stuId,stuName from (select Student.stuId,Student.stuName,score ,(select score from Scores Scores_2 where Scores_2.stuId=Student.stuId and Scores_2.courseId='002') score2

  from Student,Scores where Student.stuId=Scores.stuId and courseId='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 stuId,stuName

  from Student

  where stuId not in (select Student.stuId from Student,Scores where S.stuId=Scores.stuId and score>60);

10、查詢沒有學全所有課的同學的學號、姓名；

   select Student.stuId,Student.stuName

    from Student,Scores

    where Student.stuId=Scores.stuId group by  Student.stuId,Student.stuName having count(courseId) <(select count(courseId) 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 stuId,stuName from Student,Scores where Student.stuId=Scores.stuId and courseId in select courseId from Scores where stuId='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 Scores.stuId,stuName

from Student,Scores

where Student.stuId=Scores.stuId and courseId in (select courseId from Scores where stuId='001');

13、把“Scores”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 Scores set score=(select avg(Scores_2.score)

from Scores Scores_2

where Scores_2.courseId=Scores.courseId ) from Course,Teacher where Course.courseId=Scores.courseId and Course.teacherId=Teacher.teacherId and Teacher.teacherName='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 stuId from Scores where courseId in (select courseId from Scores where stuId='1002')

group by stuId having count(*)=(select count(*) from Scores where stuId='1002');

15、刪除學習“葉平”老師課的Scores表記錄；

Delect Scores

from course ,Teacher 

where Course.courseId=Scores.courseId and Course.teacherId= Teacher.teacherId and teacherName='葉平';

16、向Scores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 Scores select stuId,'002',(Select avg(score)

from Scores where courseId='002') from Student where stuId not in (Select stuId from Scores where courseId='002');

17、按平均成績從高到低顯示所有學生的“資料庫”、“企業管理”、“英語”三門的課程成績，按如下形式顯示： 學生ID,資料庫,企業管理,英語,有效課程數,有效平均分

SELECT stuId as 學生ID

    ,(SELECT score FROM Scores WHERE Scores.stuId=t.stuId AND courseId='004') AS 資料庫

    ,(SELECT score FROM Scores WHERE Scores.stuId=t.stuId AND courseId='001') AS 企業管理

    ,(SELECT score FROM Scores WHERE Scores.stuId=t.stuId AND courseId='006') AS 英語

    ,COUNT(*) AS 有效課程數, AVG(t.score) AS 平均成績

FROM Scores AS t

GROUP BY stuId

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.courseId As 課程ID,L.score AS 最高分,R.score AS 最低分

FROM Scores L ,Scores AS R

WHERE L.courseId = R.courseId and

    L.score = (SELECT MAX(IL.score)

                  FROM Scores AS IL,Student AS IM

                  WHERE L.courseId = IL.courseId and IM.stuId=IL.stuId

                  GROUP BY IL.courseId)

    AND

    R.score = (SELECT MIN(IR.score)

                  FROM Scores AS IR

                  WHERE R.courseId = IR.courseId

              GROUP BY IR.courseId

                );

19、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.courseId AS 課程號,max(course.courseName)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 Scores T,Course

where t.courseId=course.courseId

GROUP BY t.courseId

ORDER BY 100 * SUM(CASE WHEN  isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DEScores

20、查詢如下課程平均成績和及格率的百分數(用"1行"顯示): 企業管理（001），馬克思（002），OO&UML （003），資料庫（004）

    SELECT SUM(CASE WHEN courseId ='001' THEN score ELSE 0 END)/SUM(CASE courseId WHEN '001' THEN 1 ELSE 0 END) AS 企業管理平均分

        ,100 * SUM(CASE WHEN courseId = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN courseId = '001' THEN 1 ELSE 0 END) AS 企業管理及格百分數

        ,SUM(CASE WHEN courseId = '002' THEN score ELSE 0 END)/SUM(CASE courseId WHEN '002' THEN 1 ELSE 0 END) AS 馬克思平均分

        ,100 * SUM(CASE WHEN courseId = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN courseId = '002' THEN 1 ELSE 0 END) AS 馬克思及格百分數

        ,SUM(CASE WHEN courseId = '003' THEN score ELSE 0 END)/SUM(CASE courseId WHEN '003' THEN 1 ELSE 0 END) AS UML平均分

        ,100 * SUM(CASE WHEN courseId = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN courseId = '003' THEN 1 ELSE 0 END) AS UML及格百分數

        ,SUM(CASE WHEN courseId = '004' THEN score ELSE 0 END)/SUM(CASE courseId WHEN '004' THEN 1 ELSE 0 END) AS 資料庫平均分

        ,100 * SUM(CASE WHEN courseId = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN courseId = '004' THEN 1 ELSE 0 END) AS 資料庫及格百分數

  FROM Scores

21、查詢不同老師所教不同課程平均分從高到低顯示

 SELECT max(Z.teacherId) AS 教師ID,MAX(Z.teacherName) AS 教師姓名,C.courseId AS 課程ＩＤ,MAX(C.courseName) AS 課程名稱,AVG(score) AS 平均成績

    FROM Scores AS T,Course AS C ,Teacher AS Z

    where T.courseId=C.courseId and C.teacherId=Z.teacherId

  GROUP BY C.courseId

  ORDER BY AVG(score) DEScores

22、查詢如下課程成績第 3 名到第 6 名的學生成績單：企業管理（001），馬克思（002），UML （003），資料庫（004）

[學生ID],[學生姓名],企業管理,馬克思,UML,資料庫,平均成績

SELECT  DISTINCT top 3

  Scores.stuId As 學生學號,

    Student.stuName AS 學生姓名 ,

  T1.score AS 企業管理,

  T2.score AS 馬克思,

  T3.score AS UML,

  T4.score AS 資料庫,

  ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 總分

  FROM Student,Scores  LEFT JOIN Scores AS T1

                  ON Scores.stuId = T1.stuId AND T1.courseId = '001'

        LEFT JOIN Scores AS T2

                  ON Scores.stuId = T2.stuId AND T2.courseId = '002'

        LEFT JOIN Scores AS T3

                  ON Scores.stuId = T3.stuId AND T3.courseId = '003'

        LEFT JOIN Scores AS T4

                  ON Scores.stuId = T4.stuId AND T4.courseId = '004'

  WHERE student.stuId=Scores.stuId and

  ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)

  NOT IN

  (SELECT

        DISTINCT

        TOP 15 WITH TIES

        ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)

  FROM Scores

        LEFT JOIN Scores AS T1

                  ON Scores.stuId = T1.stuId AND T1.courseId = 'k1'

        LEFT JOIN Scores AS T2

                  ON Scores.stuId = T2.stuId AND T2.courseId = 'k2'

        LEFT JOIN Scores AS T3

                  ON Scores.stuId = T3.stuId AND T3.courseId = 'k3'

        LEFT JOIN Scores AS T4

                  ON Scores.stuId = T4.stuId AND T4.courseId = 'k4'

  ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DEScores);

23、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 Scores.courseId as 課程ID, courseName 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 Scores,Course

where Scores.courseId=Course.courseId

GROUP BY Scores.courseId,courseName;

24、查詢學生平均成績及其名次

  SELECT 1+(SELECT COUNT( distinct 平均成績)

          FROM (SELECT stuId,AVG(score) AS 平均成績

                  FROM Scores

              GROUP BY stuId

              ) AS T1

        WHERE 平均成績 > T2.平均成績) as 名次,

  stuId as 學生學號,平均成績

FROM (SELECT stuId,AVG(score) 平均成績

        FROM Scores

    GROUP BY stuId

    ) AS T2

ORDER BY 平均成績 deScores;

25、查詢各科成績前三名的記錄:(不考慮成績並列情況)

  SELECT t1.stuId as 學生ID,t1.courseId as 課程ID,score as 分數

  FROM Scores t1

  WHERE score IN (SELECT TOP 3 score

          FROM Scores

          WHERE t1.courseId= courseId

        ORDER BY score DEScores

          )

  ORDER BY t1.courseId;

26、查詢每門課程被選修的學生數

  select courseId,count(stuId) from Scores group by courseId;

27、查詢出只選修了一門課程的全部學生的學號和姓名

  select Scores.stuId,Student.stuName,count(courseId) AS 選課數

  from Scores ,Student

  where Scores.stuId=Student.stuId group by Scores.stuId ,Student.stuName having count(courseId)=1;

28、查詢男生、女生人數

Select count(stuSex) as 男生人數 from Student group by stuSex having stuSex='男';

Select count(stuSex) as 女生人數 from Student group by stuSex having stuSex='女'；

29、查詢姓“張”的學生名單

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

30、查詢同名同性學生名單，並統計同名人數

  select stuName,count(*) from Student group by stuName having  count(*)>1;;

31、1981年出生的學生名單(注：Student表中stuAge列的型別是datetime)

select stuName,  CONVERT(char (11),DATEPART(year,stuAge)) as age

from student

where  CONVERT(char(11),DATEPART(year,stuAge))='1981';

32、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 courseId,Avg(score) from Scores group by courseId order by Avg(score),courseId DEScores ;

33、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 stuName,Scores.stuId ,avg(score)

from Student,Scores

where Student.stuId=Scores.stuId group by Scores.stuId,stuName having    avg(score)>85;

34、查詢課程名稱為“資料庫”，且分數低於60的學生姓名和分數

Select stuName,isnull(score,0)

from Student,Scores,Course

where Scores.stuId=Student.stuId and Scores.courseId=Course.courseId and  Course.courseName='資料庫'and score <60;

35、查詢所有學生的選課情況；

SELECT Scores.stuId,Scores.courseId,stuName,courseName

FROM Scores,Student,Course

where Scores.stuId=Student.stuId and Scores.courseId=Course.courseId ;

36、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.stuId,student.stuName,Scores.courseId,Scores.score

FROM student,Scores

WHERE Scores.score>=70 AND Scores.stuId=student.stuId;

37、查詢不及格的課程，並按課程號從大到小排列

select courseId from Scores where Scoresor e <60 order by courseId ;

38、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 Scores.stuId,Student.stuName from Scores,Student where Scores.stuId=Student.stuId and score>80 and courseId='003';

39、求選了課程的學生人數

select count(*) from Scores;

40、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.stuName,score

from Student,Scores,Course C,Teacher

where Student.stuId=Scores.stuId and Scores.courseId=C.courseId and C.teacherId=Teacher.teacherId and Teacher.teacherName='葉平' and Scores.score=(select max(score)from Scores where courseId=C.courseId );

41、查詢各個課程及相應的選修人數

select count(*) from Scores group by courseId;

42、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.stuId,B.score from Scores A  ,Scores B where A.score=B.score and A.courseId <>B.courseId ;

43、查詢每門功成績最好的前兩名

SELECT t1.stuId as 學生ID,t1.courseId as 課程ID,score as 分數

  FROM Scores t1

  WHERE score IN (SELECT TOP 2 score

          FROM Scores

          WHERE t1.courseId= courseId

        ORDER BY score DEScores

          )

  ORDER BY t1.courseId;

44、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  courseId as 課程號,count(*) as 人數

from  Scores 

group  by  courseId

order  by  count(*) deScores,courseId

45、檢索至少選修兩門課程的學生學號

select  stuId 

from  Scores 

group  by  stuId

having  count(*)  >  =  2

46、查詢全部學生都選修的課程的課程號和課程名

select  courseId,courseName 

from  Course 

where  courseId  in  (select  courseId  from  Scores group  by  courseId)

47、查詢沒學過“葉平”老師講授的任一門課程的學生姓名

select stuName from Student where stuId not in (select stuId from Course,Teacher,Scores where Course.teacherId=Teacher.teacherId and Scores.courseId=course.courseId and teacherName='葉平');

48、查詢兩門以上不及格課程的同學的學號及其平均成績

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

49、檢索“004”課程分數小於60，按分數降序排列的同學學號

select stuId from Scores where courseId='004'and score <60 order by score deScores;

50、刪除“002”同學的“001”課程的成績

d

elete from Scores where stuId='002'and courseId='001';

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