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网上流行的学生选课相关的50个常用sql语句

学生表 Student(S#,Sname,Sage,Ssex)

教师表 Teacher(T#,Tname)

课程表 Course(C#,Cname,T#)

学生成绩表 SC(S#,C#,score)

问题:

1、查询“001”课程比“002”课程成绩高的所有学生的学号;

SELECT  a.s#FROM    ( SELECT    *          FROM      dbo.SC          WHERE     c# = 001        ) a        INNER JOIN ( SELECT *                     FROM   dbo.SC                     WHERE  c# = 002                   ) b ON a.s# = b.s#WHERE   a.score > b.score

 

2、查询平均成绩大于60分的同学的学号和平均成绩;

SELECT  s# ,        AVG(score)FROM    dbo.SCGROUP BY s#HAVING  AVG(score) > 60 

 

3、查询所有同学的学号、姓名、选课数、总成绩;

SELECT  a.s# ,        a.sname ,        COUNT(b.c#) ,        SUM(b.score)FROM    dbo.Student a        LEFT OUTER JOIN dbo.SC b ON a.s# = b.s#GROUP BY a.s# ,        a.sname

 

4、查询姓“李”的老师的个数;

SELECT  COUNT(DISTINCT tname)FROM    dbo.TeacherWHERE   tname LIKE 李%

 

5、查询没学过“叶平”老师课的同学的学号、姓名;

SELECT  Student.S# ,        Student.SnameFROM    StudentWHERE   S# NOT IN ( SELECT DISTINCT                            ( SC.S# )                    FROM    SC ,                            Course ,                            Teacher                    WHERE   SC.C# = Course.C#                            AND Teacher.T# = Course.T#                            AND Teacher.Tname = 叶平 )

 

6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名;

SELECT  Student.S# ,        Student.SnameFROM    Student ,        SCWHERE   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、查询学过“叶平”老师所教的所有课的同学的学号、姓名;

SELECT  S# ,        SnameFROM    StudentWHERE   S# IN ( SELECT  S#                FROM    SC ,                        Course ,                        Teacher                WHERE   SC.C# = Course.C#                        AND Teacher.T# = Course.T#                        AND Teacher.Tname = 叶平                GROUP BY S#                HAVING  COUNT(SC.C#) = ( SELECT COUNT(C#)                                         FROM   Course ,                                                Teacher                                         WHERE  Teacher.T# = Course.T#                                                AND Tname = 叶平                                       ) )

 

8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名;

SELECT  S# ,        SnameFROM    ( 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_2WHERE   score2 < score

 

9、查询所有课程成绩小于60分的同学的学号、姓名;

SELECT  S# ,        SnameFROM    StudentWHERE   S# NOT IN ( SELECT  Student.S#                    FROM    Student ,                            SC                    WHERE   Student.S# = SC.S#                            AND score > 60 )

 

10、查询没有学全所有课的同学的学号、姓名;

SELECT  Student.S# ,        Student.SnameFROM    Student ,        SCWHERE   Student.S# = SC.S#GROUP BY Student.S# ,        Student.SnameHAVING  COUNT(C#) < ( SELECT    COUNT(C#)                      FROM      Course                    )

 

11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名;

SELECT  S# ,        SnameFROM    Student ,        SCWHERE   Student.S# = SC.S#        AND C# IN ( SELECT  C#                    FROM    SC                    WHERE   S# = 1001 )

 

12、查询至少学过学号为“001”同学所有一门课的其他同学学号和姓名;

SELECT DISTINCT        SC.S# ,        SnameFROM    Student ,        SCWHERE   Student.S# = SC.S#        AND C# IN ( SELECT  C#                    FROM    SC                    WHERE   S# = 001 )

 

13、把“SC”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩;

UPDATE  SCSET     score = ( SELECT    AVG(SC_2.score)                  FROM      SC SC_2                  WHERE     SC_2.C# = SC.C#                )FROM    Course ,        TeacherWHERE   Course.C# = SC.C#        AND Course.T# = Teacher.T#        AND Teacher.Tname = 叶平

 

14、查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名;

SELECT  S#FROM    SCWHERE   C# IN ( SELECT  C#                FROM    SC                WHERE   S# = 1002 )GROUP BY S#HAVING  COUNT(*) = ( SELECT COUNT(*)                     FROM   SC                     WHERE  S# = 1002                   )

 

15、删除学习“叶平”老师课的SC表记录;

DELETE  SCFROM    course ,        TeacherWHERE   Course.C# = SC.C#        AND Course.T# = Teacher.T#        AND Tname = 叶平

 

16、向SC表中插入一些记录,这些记录要求符合以下条件:没有上过编号“003”课程的同学学号、2、 号课的平均成绩;

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、按平均成绩从高到低显示所有学生的“数据库”、“企业管理”、“英语”三门的课程成绩,按如下形式显示: 学生ID,,数据库,企业管理,英语,有效课程数,有效平均分

SELECT  S# AS 学生ID ,        ( SELECT    score          FROM      SC          WHERE     SC.S# = t.S#                    AND C# = 004        ) AS 数据库 ,        ( SELECT    score          FROM      SC          WHERE     SC.S# = t.S#                    AND C# = 001        ) AS 企业管理 ,        ( SELECT    score          FROM      SC          WHERE     SC.S# = t.S#                    AND C# = 006        ) AS 英语 ,        COUNT(*) AS 有效课程数 ,        AVG(t.score) AS 平均成绩FROM    SC AS tGROUP BY S#ORDER BY AVG(t.score) 

 

18、查询各科成绩最高和最低的分:以如下形式显示:课程ID,最高分,最低分

SELECT  L.C# AS 课程ID ,        L.score AS 最高分 ,        R.score AS 最低分FROM    SC L ,        SC AS RWHERE   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、按各科平均成绩从低到高和及格率的百分数从高到低顺序

SELECT  t.C# AS 课程号 ,        MAX(course.Cname) AS 课程名 ,        ISNULL(AVG(score), 0) AS 平均成绩 ,        100 * SUM(CASE WHEN ISNULL(score, 0) >= 60 THEN 1                       ELSE 0                  END) / COUNT(*) AS 及格百分数FROM    SC T ,        CourseWHERE   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、查询如下课程平均成绩和及格率的百分数(用"1行"显示): 企业管理(001),马克思(002),OO&UML (003),数据库(004)

SELECT SUM(CASE WHEN C# =001 THEN score ELSE 0 END)/SUM(CASE C# WHEN 001 THEN 1 ELSE 0 END) AS 企业管理平均分 ,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 企业管理及格百分数 ,SUM(CASE WHEN C# = 002 THEN score ELSE 0 END)/SUM(CASE C# WHEN 002 THEN 1 ELSE 0 END) AS 马克思平均分 ,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 马克思及格百分数 ,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及格百分数 ,SUM(CASE WHEN C# = 004 THEN score ELSE 0 END)/SUM(CASE C# WHEN 004 THEN 1 ELSE 0 END) AS 数据库平均分 ,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 数据库及格百分数 FROM SC 

 

21、查询不同老师所教不同课程平均分从高到低显示

SELECT max(Z.T#) AS 教师ID,MAX(Z.Tname) AS 教师姓名,C.C# AS 课程ID,MAX(C.Cname) AS 课程名称,AVG(Score) AS 平均成绩 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、查询如下课程成绩第 3 名到第 6 名的学生成绩单:企业管理(001),马克思(002),UML (003),数据库(004) [学生ID],[学生姓名],企业管理,马克思,UML,数据库,平均成绩

SELECT DISTINCT top 3 SC.S# As 学生学号, Student.Sname AS 学生姓名 , T1.score AS 企业管理, T2.score AS 马克思, T3.score AS UML, T4.score AS 数据库, ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 总分 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、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60]

SELECT SC.C# as 课程ID, Cname as 课程名称 ,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、查询学生平均成绩及其名次

SELECT 1+(SELECT COUNT( distinct 平均成绩) FROM (SELECT S#,AVG(score) AS 平均成绩 FROM SC GROUP BY S# ) AS T1 WHERE 平均成绩 > T2.平均成绩) as 名次, S# as 学生学号,平均成绩 FROM (SELECT S#,AVG(score) 平均成绩 FROM SC GROUP BY S# ) AS T2 ORDER BY 平均成绩 desc

 

25、查询各科成绩前三名的记录:(不考虑成绩并列情况)

SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数 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、查询每门课程被选修的学生数

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

 

27、查询出只选修了一门课程的全部学生的学号和姓名

select SC.S#,Student.Sname,count(C#) AS 选课数 from SC ,Student where SC.S#=Student.S# group by SC.S# ,Student.Sname having count(C#)=1; 

 

28、查询男生、女生人数

Select count(Ssex) as 男生人数 from Student group by Ssex having Ssex=; Select count(Ssex) as 女生人数 from Student group by Ssex having Ssex=; 

 

29、查询姓“张”的学生名单

SELECT Sname FROM Student WHERE Sname like 张%; 

 

30、查询同名同性学生名单,并统计同名人数

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

 

31、1981年出生的学生名单(注:Student表中Sage列的类型是datetime)

select Sname, CONVERT(char (11),DATEPART(year,Sage)) as age from student where CONVERT(char(11),DATEPART(year,Sage))=1981; 

 

32、查询每门课程的平均成绩,结果按平均成绩升序排列,平均成绩相同时,按课程号降序排列

Select C#,Avg(score) from SC group by C# order by Avg(score),C# DESC ; 

 

33、查询平均成绩大于85的所有学生的学号、姓名和平均成绩

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

 

34、查询课程名称为“数据库”,且分数低于60的学生姓名和分数  

Select Sname,isnull(score,0) from Student,SC,Course where SC.S#=Student.S# and SC.C#=Course.C# and Course.Cname=数据库and score <60; 

 

35、查询所有学生的选课情况;

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

 

36、查询任何一门课程成绩在70分以上的姓名、课程名称和分数;

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

 

37、查询不及格的课程,并按课程号从大到小排列

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

 

38、查询课程编号为003且课程成绩在80分以上的学生的学号和姓名;

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

 

39、求选了课程的学生人数

select count(*) from sc; 

 

40、查询选修“叶平”老师所授课程的学生中,成绩最高的学生姓名及其成绩

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=叶平 and SC.score=(select max(score)from SC where C#=C.C# ); 

 

41、查询各个课程及相应的选修人数

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

 

42、查询不同课程成绩相同的学生的学号、课程号、学生成绩

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

 

43、查询每门功成绩最好的前两名

SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数 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、统计每门课程的学生选修人数(超过10人的课程才统计)。要求输出课程号和选修人数,查询结果按人数降序排列,查询结果按人数降序排列,若人数相同,按课程号升序排列

select C# as 课程号,count(*) as 人数 from sc group by C# order by count(*) desc,c# 

 

45、检索至少选修两门课程的学生学号

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

 

46、查询全部学生都选修的课程的课程号和课程名

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

 

47、查询没学过“叶平”老师讲授的任一门课程的学生姓名 

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=叶平); 

 

48、查询两门以上不及格课程的同学的学号及其平均成绩

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、检索“004”课程分数小于60,按分数降序排列的同学学号

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

 

50、删除“002”同学的“001”课程的成绩

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

 

网上流行的学生选课相关的50个常用sql语句