—————-50條常用語句（以學生表為例）———

Student(S#,Sname,Sage,Ssex) 學生表

 

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“”課程比“”課程成績高的所有學生的學號；

 

  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、查詢平均成績大於分的同學的學號和平均成績；

 

    SELECT S#,avg(score) 

 

    FROM sc 

 

    GROUP BY S# having avg(score) >60; 

 

3、查詢所有同學的學號、姓名、選課數、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；

 

  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.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、查詢學過“”並且也學過編號“”課程的同學的學號、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、查詢學過“葉平”老師所教的所有課的同學的學號、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“”的成績比課程編號“”課程低的所有同學的學號、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於分的同學的學號、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、查詢沒有學全所有課的同學的學號、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號為“”的同學所學相同的同學的學號和姓名；

 

    SELECT S#,Sname FROM Student,SC WHERE Student.S#=SC.S# AND C# in SELECT C# FROM SC WHERE S#='1001'; 

 

12、查詢至少學過學號為“”同學所有一門課的其他同學學號和姓名；

 

    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“”號的同學學習的課程完全相同的其他同學學號和姓名；

 

    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、刪除學習“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“”課程的同學學號、、

 

    號課的平均成績；

 

    Insert SC SELECT S#,'002',(SELECT avg(score) 

 

    FROM SC WHERE C#='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 S# as 學生ID 

 

        ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 資料庫

 

        ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企業管理

 

        ,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='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 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數從高到低順序

 

    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 及格百分數

 

    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（），馬克思（），OO&UML （），資料庫（）

 

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

 

        ,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 企業管理及格百分數

 

        ,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 馬克思及格百分數

 

        ,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及格百分數

 

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

 

        ,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 資料庫及格百分數

 

  FROM SC 

 

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.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 Z 

 

    WHERE T.C#=C.C# AND C.T#=Z.T# 

 

  GROUP BY C.C# 

 

  ORDER BY AVG(Score) DESC 

 

22、查詢如下課程成績第3 名到第6 名的學產生績單：企業管理（），馬克思（），UML （），資料庫（）

 

    [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 

 

      SC.S# As 學生學號, 

 

        Student.Sname 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,SC  LEFT 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' 

 

      WHERE student.S#=SC.S# 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 sc 

 

            LEFT 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 BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC); 

 

 

 

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 SC.C# 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.C#=Course.C# 

 

    GROUP BY SC.C#,Cname; 

 

 

 

24、查詢學生平均成績及其名次

 

      SELECT 1+(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 學生學號,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:(不考慮成績並列情況) 

 

      SELECT t1.S# as 學生ID,t1.C# as 課程ID,Score as 分數

 

      FROM SC t1 

 

      WHERE score 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生數

 

  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生的學號和姓名

 

  SELECT SC.S#,Student.Sname,count(C#) AS 選課數

 

  FROM SC ,Student 

 

  WHERE SC.S#=Student.S# GROUP BY SC.S# ,Student.Sname having count(C#)=1; 

 

28、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'；

 

29、查詢姓“張”的學生名單

 

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

 

30、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;; 

 

31、年出生的學生名單(註：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、查詢平均成績大於的所有學生的學號、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“資料庫”，且分數低於的學生姓名和分數

 

    SELECT Sname,isnull(score,0) 

 

    FROM Student,SC,Course 

 

    WHERE SC.S#=Student.S# AND SC.C#=Course.C# AND  Course.Cname='資料庫'and score <60; 

 

35、查詢所有學生的選課情況；

 

    SELECT SC.S#,SC.C#,Sname,Cname 

 

    FROM SC,Student,Course 

 

    WHERE SC.S#=Student.S# AND SC.C#=Course.C# ; 

 

36、查詢任何一門課程成績在分以上的姓名、課程名稱和分數；

 

    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，並按課程號從大到小排列

 

    SELECT c# FROM sc WHERE scor e <60 ORDER BY C# ; 

 

38、查詢課程編號為且課程成績在分以上的學生的學號和姓名；

 

    SELECT SC.S#,Student.Sname FROM SC,Student WHERE SC.S#=Student.S# AND Score>80 AND C#='003'; 

 

39、求選了課程的學生人數

 

    SELECT count(*) FROM sc; 

 

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.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的選修人數

 

    SELECT count(*) FROM sc GROUP BY C#; 

 

42、查詢不同課程成績相同的學生的學號、課程號、學產生績

 

  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 學生ID,t1.C# as 課程ID,Score as 分數

 

      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、統計每門課程的學生選修人數（超過人的課程才統計）。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  C# as 課程號,count(*) as 人數

 

    FROM  sc  

 

    group  by  C# 

 

    order  by  count(*) desc,c#  

 

45、檢索至少選修兩門課程的學生學號

 

    SELECT  S#  

 

    FROM  sc  

 

    group  by  s# 

 

    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  C#,Cname  

 

    FROM  Course  

 

    WHERE  C#  in  (SELECT  c#  FROM  sc group  by  c#)  

 

47、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 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的學號及其平均成績

 

    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“”課程分數小於，按分數降序排列的同學學號

 

    SELECT S# FROM SC WHERE C#='004'and score <60 ORDER BY score desc; 

 

50、刪除“”同學的“”課程的成績

 

delete FROM Sc WHERE S#='001'and C#='001';