经典SQL查询题目
2018-09-20 17:27 misswjr 阅读(4028) 评论(0) 编辑 收藏 举报SQL查询题目
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SQL查询题目
条件：
Student(Sno,Sname,Sage,Ssex) 学生表
Course(Cno,Cname,Tno) 课程表
SC(Sno,Cno,score) 成绩表（选课表）
Teacher(Tno,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.sno from (select sno,score from SC where cno='001') a,(select sno,score
from SC where cno='002') b
where a.score>b.score and a.sno=b.sno;
2、查询平均成绩大于60分的同学的学号和平均成绩；
select SNO,avg(score) from sc group by SNO having avg(score) >60;
3、查询所有同学的学号、姓名、选课数、总成绩；
select Student.SNO,Student.Sname,count(SC.CNO),sum(score)
from Student left Outer join SC on Student.SNO=SC.SNO
group by Student.SNO,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.SNO,Student.Sname from Student
where SNO not in (select distinct(SC.SNO) from SC,Course,Teacher where SC.CNO=Course.CNO and Teacher.Tno=Course.Tno 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.SNO,Student.Sname from Student,SC where Student.SNO=SC.SNO and SC.CNO='001'and exists( Select * from SC as SC_2 where SC_2.SNO=SC.SNO and SC_2.CNO='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 SNO,Sname
from Student
where SNO in (select SNO from SC ,Course ,Teacher where SC.CNO=Course.CNO and Teacher.TNO=Course.TNO and Teacher.Tname='叶平' group by SNO having count(SC.CNO)=(select count(CNO) from Course,Teacher where Teacher.TNO=Course.TNO 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 SNO,Sname from (select Student.SNO,Student.Sname,score ,(select score from SC SC_2 where SC_2.SNO=Student.SNO and SC_2.CNO='002') score2
from Student,SC where Student.SNO=SC.SNO and CNO='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 SNO,Sname
from Student
where SNO not in (select Student.SNO from Student,SC where S.SNO=SC.SNO and score>60);
10、查询没有学全所有课的同学的学号、姓名；
select Student.SNO,Student.Sname
from Student,SC
where Student.SNO=SC.SNO group by Student.SNO,Student.Sname having count(CNO) <(select count(CNO) 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 SNO,Sname from Student,SC where Student.SNO=SC.SNO and CNO in select CNO from SC where SNO='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.SNO,Sname
from Student,SC
where Student.SNO=SC.SNO and CNO in (select CNO from SC where SNO='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.CNO=SC.CNO) from Course,Teacher where Course.CNO=SC.CNO and Course.TNO=Teacher.TNO 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 SNO from SC where CNO in (select CNO from SC where SNO='1002')
group by SNO having count(*)=(select count(*) from SC where SNO='1002');
15、删除学习“叶平”老师课的SC表记录；
DelectSC
from course ,Teacher
where Course.CNO=SC.CNO and Course.TNO= Teacher.TNO 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 SNO,'002',(Select avg(score)
from SC where CNO='002') from Student where SNO not in (Select SNO from SC where CNO='002');
17、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 SNO as 学生ID
,(SELECT score FROM SC WHERE SC.SNO=t.SNO AND CNO='004') AS 数据库
,(SELECT score FROM SC WHERE SC.SNO=t.SNO AND CNO='001') AS 企业管理
,(SELECT score FROM SC WHERE SC.SNO=t.SNO AND CNO='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 SNO
ORDER BY avg(t.score)
18、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.CNO 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.CNO=course.CNO
GROUP BY t.CNO
ORDER BY 100 * SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT(*) DESC
19、查询不同老师所教不同课程平均分从高到低显示
SELECT max(Z.TNO) AS 教师ID,MAX(Z.Tname) AS 教师姓名,C.CNO 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.CNO=C.CNO and C.TNO=Z.TNO
GROUP BY C.CNO
ORDER BY AVG(Score) DESC
20、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.CNO 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.CNO=Course.CNO
GROUP BY SC.CNO,Cname;
21、查询各科成绩前三名的记录:(不考虑成绩并列情况)
SELECT t1.SNO as 学生ID,t1.CNO as 课程ID,Score as 分数
FROM SC t1
WHERE score IN (SELECT TOP 3 score
FROM SC
WHERE t1.CNO= CNO
ORDER BY score DESC
)
ORDER BY t1.CNO;
22、查询每门课程被选修的学生数
select cno,count(SNO) from sc group by CNO;
23、查询出只选修了一门课程的全部学生的学号和姓名
select SC.SNO,Student.Sname,count(CNO) AS 选课数
from SC ,Student
where SC.SNO=Student.SNO group by SC.SNO ,Student.Sname having count(CNO)=1;
24、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'；
25、查询姓“张”的学生名单
SELECT Sname FROM Student WHERE Sname like '张%';
26、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;
27、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';
28、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 CNO,Avg(score) from SC group by CNO order by Avg(score),CNO DESC ;
29、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.SNO ,avg(score)
from Student,SC
where Student.SNO=SC.SNO group by SC.SNO,Sname having avg(score)>85;
30、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.SNO=Student.SNO and SC.CNO=Course.CNO and Course.Cname='数据库'and score <60;
31、查询所有学生的选课情况；
SELECT SC.SNO,SC.CNO,Sname,Cname
FROM SC,Student,Course
where SC.SNO=Student.SNO and SC.CNO=Course.CNO ;
32、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.SNO,student.Sname,SC.CNO,SC.score
FROM student,Sc
WHERE SC.score>=70 AND SC.SNO=student.SNO;
33、查询不及格的课程，并按课程号从大到小排列
select cno from sc where scor e <60 order by CNO ;
34、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.SNO,Student.Sname from SC,Student where SC.SNO=Student.SNO and Score>80 and CNO='003';
35、求选了课程的学生人数
select count(*) from sc;
36、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.SNO=SC.SNO and SC.CNO=C.CNO and C.TNO=Teacher.TNO and Teacher.Tname='叶平' and SC.score=(select max(score)from SC where CNO=C.CNO );
37、查询各个课程及相应的选修人数
select count(*) from sc group by CNO;
38、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.SNO,B.score from SC A ,SC B where A.Score=B.Score and A.CNO <>B.CNO ;
39、查询每门功成绩最好的前两名
SELECT t1.SNO as 学生ID,t1.CNO as 课程ID,Score as 分数
FROM SC t1
WHERE score IN (SELECT TOP 2 score
FROM SC
WHERE t1.CNO= CNO
ORDER BY score DESC
)
ORDER BY t1.CNO;
40、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 CNO as 课程号,count(*) as 人数
from sc
group by CNO
order by count(*) desc,cno
41、检索至少选修两门课程的学生学号
select SNO
from sc
group by sno
having count(*) > = 2
42、查询全部学生都选修的课程的课程号和课程名
select CNO,Cname
from Course
where CNO in (select cno from sc group by cno)
43、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 SNO not in (select SNO from Course,Teacher,SC where Course.TNO=Teacher.TNO and SC.CNO=course.CNO and Tname='叶平');
44、查询两门以上不及格课程的同学的学号及其平均成绩
select SNO,avg(isnull(score,0)) from SC where SNO in (select SNO from SC where score <60 group by SNO having count(*)>2)group by SNO;
45、检索“004”课程分数小于60，按分数降序排列的同学学号
select SNO from SC where CNO='004'and score <60 order by score desc;
46、删除“002”同学的“001”课程的成绩
delete from Sc where SNO='001'and CNO='001';
