学生、成绩、课程表面试题和答案

迈不过友情╰ 2022-01-05 06:25 219阅读 0赞

Student(S\#,Sname,Sage,Ssex) 学生表  
Course(C\#,Cname,T\#) 课程表  
SC(S\#,C\#,score) 成绩表  
Teacher(T\#,Tname) 教师表

创建表：

create table Student(S# varchar(20),Sname varchar(10),Sage int,Ssex varchar(2))

前面加一列序号：

if
    exists(select table_name from information_schema.tables
      where table_name='Temp_Table')
    drop table Temp_Table
    go
    select 排名=identity(int,1,1),* INTO   Temp_Table    from Student 
    go
    select * from Temp_Table
    go 
     
    drop database [ ]  --删除空的没有名字的数据库

问题：  
**1、查询“”课程比“”课程成绩高的所有学生的学号；**

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、查询平均成绩大于分的同学的学号和平均成绩；**

select S#,avg(score) 
    from sc 
    group 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 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、查询姓“李”的老师的个数；**

select count(distinct(Tname)) 
      from Teacher 
      where 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.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='叶平');

**6、查询学过“”并且也学过编号“”课程的同学的学号、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、查询学过“叶平”老师所教的所有课的同学的学号、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='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“”的成绩比课程编号“”课程低的所有同学的学号、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、查询所有课程成绩小于分的同学的学号、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、查询没有学全所有课的同学的学号、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、查询至少有一门课与学号为“”的同学所学相同的同学的学号和姓名；**

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

**12、查询至少学过学号为“”同学所有一门课的其他同学学号和姓名；**

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“叶平”老师教的课的成绩都更改为此课程的平均成绩；**

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='叶平');

**14、查询和“”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 SC where 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；**

Delect SC  from course ,Teacher  
    where 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“”课程的同学学号、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 t 
    GROUP 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 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,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（），马克（），OO&UML （），数据库（）**

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名到第名的学生成绩单：企业管理（），马克（），UML （），数据库（）  
\[学生ID\],\[学生姓名\],企业管理,马克,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, 
          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='男'; 
    Select count(Ssex) as 女生人数from Student group by Ssex having Ssex='女'；

**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、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';