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 * from sc where c#=’001’) a,(select * from sc where c#=’002’) b
where a.score>b.score 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 a.c#,a.sname,count(b.c#),sum(b.score) from student a left Outer join SC b b.s#=a.s# join
GROUP BY a.sid,aSname
4、查询姓“李”的老师的个数;
select count(t#) from Teacher where tname=’li’
5、查询没学过“叶平”老师课的同学的学号、姓名;
SELECT
distinct(
Teacher.id=Course.tid 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;
Student.sid,Student.Sname
SC,Course,Teacher
SC.cid=Course.cid
(SELECT
AND
WHERE
sid
not
in
FROM
Student
SC.sid)
FROM
WHERE
select S#,Sname from Student where S# in(select distinct(S#)
from SC where SC.C#='1') AND S# in (select distinct(S#)
from SC where SC.C#='2')
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
a.s# from Student a,SC d,Course b,Teacher c where a.s#=d.s#
and d.c#=b.C# and b.t#=c.t# and c.tname='b1' group by a.s# having count(a.s#)=(
select count(b.c#) from Teacher a,Course b where a.t#=b.t# and a.tname='b1'))
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 d.s#,c.sname from
(select * from SC WHERE C#='1') d,
(select * from SC WHERE C#='2') b,Student c
where d.score>b.score and d.s#=b.s# and c.s#=d.s#
或者是
select a.s#,a.sname from(select student.s#,sname,score,(select score from
sc where student.s#=sc.s# and sc.c#='1') as scroe2 from student,sc where
student.s#=sc.s# and sc.c#='2') a where a.score
where student.s#=sc.s# and sc.score<60)
10、查询没有学全所有课的同学的学号、姓名;
select a.s#,a.sname from student a join sc b
on a.s#=b.s# group by a.s#,a.sname
having count(b.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 distinct student.s#,sname from
student,sc where student.s#=sc.s# and student.s#<>'1' and sc.c# in(select
course.c# from course,sc where course.c#=sc.c# and sc.s#='1')
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;
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;
UPADTE sc SET SCORE=(SELECT
AVG(SC.SCORE) FROM SC,COURSE,TEACHAR WHERE
TACHAR.TNAME=’b1’) where
c# from sc,coure,tachar, where sc.c#=coure.c# and coure.t#=tachar.t# and
SC.C#=COURE.C# AND COURE.T#=TACHAR.T# WHERE
sc=(select
tachar.tname=’b1’)
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 sc.s#,student.sname from sc,student where sc.s#=student.s# and c# in (select c# from sc
where s#='1')
group by sc.s#,student.sname having count(*)=(select count(*) from sc where s#='1')
此题考查了in的理解
15、删除学习“叶平”老师课的SC表记录;
delete from sc where c# in(select c# from course a,teacher b where
a.t#=b.t# and b.tname='b1')
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 into sc select sc.s#,2,avg(sc.score) from sc,Course where
sc.c#=Course.c# and Course.c#<>'4' group by sc.s#
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 distinct a.s#,(select sc.score from sc,course
where sc.s#=a.s# and sc.c#=course.c# and course.cname='yuwen') 'yuwen',
(select sc.score from sc,course
where sc.s#=a.s# and sc.c#=course.c# and course.cname='tiyu') 'tiyu',
(select sc.score from sc,course
where sc.s#=a.s# and sc.c#=course.c# and course.cname='shuxue') 'shuxue'
,count(*),avg(score)
from
course.cname='yuwen' or course.cname='tiyu')
group by a.s#
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
sc a where a.c# in(select C# from course where course.cname='shuxue' or
select sc.c# '课程ID',max(sc.score) '最高分',min(sc.score) '最低分' from sc group by sc.C#或
者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 a.C#,avg(score) as ' 平 均 分 ',sum(case when isnull(score,0)>=60 then 1 else 0
end),count(*),
cast(100*sum(case when isnull(score,0)>=60 then 1 else 0 end)/count(*) as nvarchar(10))+'%' as '
百分比'
from sc a group by a.c#
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 c# when '1' then score else 0 end)/sum(case c# when '1' then 1 else 0 end) as '1课
程平均成绩',
100*sum(case when c#='1' and score>60 then 1 else 0 end)/sum(case c# when '1' then 1 else 0 end)
as '1课程及格率',
sum(case c# when '2' then score else 0 end)/sum(case c# when '2' then 1 else 0 end) as '2课程平均
成绩',
sum(case when c#='2' and score>60 then 1 else 0 end)/sum(case c# when '2' then 1 else 0 end)as '2
课程及格率'
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(c.C#),max(tname),max(cname),avg(score) from teacher a,course b,sc c where a.t#=b.t#
and b.c#=c.c#
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
group by c.C# order by avg(score)
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#,cname,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 '[70-85]',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 T1 WHERE 平均成绩> T2.平均成绩) as 名次, S# as 学生学号,平均
AS 平均成绩FROM SC
GROUP BY S#
成绩
22、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)
26、查询每门课程被选修的学生数
27、查询出只选修了一门课程的全部学生的学号和姓名
28、查询男生、女生人数
29、查询姓“张”的学生名单
30、查询同名同性学生名单,并统计同名人数
31、1981 年出生的学生名单(注:Student 表中 Sage 列的类型是 datetime)
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
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
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
35、查询所有学生的选课情况;
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;
37、查询不及格的课程,并按课程号从大到小排列
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;
39、求选了课程的学生人数
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
41、查询各个课程及相应的选修人数
42、查询不同课程成绩相同的学生的学号、课程号、学生成绩
43、查询每门功成绩最好的前两名
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
45、检索至少选修两门课程的学生学号
46、查询全部学生都选修的课程的课程号和课程名
47、查询没学过“叶平”老师讲授的任一门课程的学生姓名
48、查询两门以上不及格课程的同学的学号及其平均成绩
49、检索“004”课程分数小于 60,按分数降序排列的同学学号
50、删除“002”同学的“001”课程的成绩