不错的SQL面试题（一）

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

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 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60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%';

新解：

select count(*) from Teacher where Tname like '李%' 或者 select count(*) from Teacher where left(Tname,1) =  '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“001”并且也学过编号“002”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“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#,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60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“1001”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“001”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“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 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“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 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（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='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、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 scor e
<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
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#='004'and
score <60
order
by score desc;

50、删除“002”同学的“001”课程的成绩

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

转原文地址 http://topic.csdn.net/u/20081020/15/1abf54d0-f401-42ab-a75e-df90027ceba0.html