/*
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
*/
--1、查询“001”课程比“002”课程成绩高的所有学生的学号;
select s1.s#
from SC s1,SC s2
where s1.s#=s2.s# and s1.c#='001'and s2.c#='002'ands1.score>s2.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.s#,avg(s.score)
from SC s
groupby s.s#
havingavg(s.score)>60;
--3、查询所有同学的学号、姓名 、选课数、总成绩;
select d.s#,max(d.sname),count(distinct s.c#),sum(s.score)
from Student d,SC s
where d.s#=s.s#
groupby d.s#;
--4、查询姓“李”的老师的个数;
selectcount(0)
from Teacher t
where t.tname like'李%';
--5、查询没学过“叶平”老师课的同学的学号、姓名;
select d.s#,d.sname
from Student d
wherenotexists(
selectdistinct(s.s#)
from SC s,Teachert,Course c
where t.t#=c.t# and s.c#=c.c# and t.tname='叶平'and d.s#=s.s#);
--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 d.s#, d.sname
from Student d, SC s
where s.s# = d.s# and s.c# ='001'andexists
(select s1.s# from SC s1 where s1.s# = s.s# and s1.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.s#,max(d.sname)
from SC s,Studentd,Course c,Teachert
where s.s#=d.s# and s.c#=c.c# and c.t#=t.t# and t.tname='叶平'
groupby s.s#
havingcount(distinct s.c#)=(
selectcount(0)from Coursec,Teachert where c.t#=t.t# and t.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 d.s#,d.sname
from SC s1,SC s2,Studentd
where s1.s#=s2.s# and s1.s#=d.s# and s1.c#='002'and s2.c#='001'ands1.score<s2.score;
--9、查询所有课程成绩小于60分的同学的学号、姓名;
select s.s#,max(d.sname)
from Student d,SC s
where d.s#=s.s# and s.score<60
groupby s.s#
havingcount(0)=(selectcount(0)from SC s1 where s.s#=s1.s#);
--10、查询没有学全所有课的同学的学号、姓名;
select s.s#,max(d.sname)
from Student d,SC s
where d.s#=s.s#
groupby s.s#
havingcount(distinct s.c#)<>(selectcount(0)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;
selectdistinct s.s#,d.sname
from Student d,SC s
where d.s#=s.s# and s.s#<>'1001'andexists(
select s1.c# from SC s1 where s1.s#='1001'and s.c#=s1.c# );
--12、查询至少学过学号为“1010”同学所有一门课的其他同学学号和姓名;
selectdistinct s.s#,d.sname
from Student d,SC s
where d.s#=s.s# and s.s#<>'1010'and s.c# in(
select s1.c# from SC s1 where s1.s#='1010');
--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 s
set s.score =
(selectavg(s1.score)from SC s1 where s.c# = s1.c#)
whereexists(select s.c#
from Coursec, Teachert
where s.c# = c.c# and c.t# = t.t# and t.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.s#,max(d.sname)
from Studentd,SC s
where d.s#=s.s# and s.s#<>'1002'andexists(
select c# from SC where s#='1002'and s.c#=c#)
groupby s.s#
havingcount(0)=(selectcount(0)from SC where s#='1002')
and count((select count(0) from SC wheres#=s.s#))=(select count(0) from SC where s#='1002');
--15、删除学习“叶平”老师课的SC表记录;
delete SC s whereexists(select s.c# from Coursec,Teachert
where s.c#=c.c# and c.t#=t.t# and t.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、002号课的平均成绩;
insertinto SC
(select d.s#,'002',(selectround(avg(score),2)from SC where c#='002')
from Student d wherenotexists(selectdistinct s.s# from SC s where s.s#=d.s# and s.c#='003'));
--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.s# as学生ID,
(select avg(s1.score)from SC s1,Course c where s1.c#=c.c# and s.s#=s1.s# andc.cname='Java编程思想')as Java编程思想,
(select avg(s1.score)from SC s1,Course c where s1.c#=c.c# and s.s#=s1.s# andc.cname='Struts2基础')as Struts2基础,
(select avg(s1.score)from SC s1,Course c where s1.c#=c.c# and s.s#=s1.s# andc.cname='Spring基础')as Spring基础,
count(0)as有效课程数,round(avg(s.score),2)as有效平均分
from SC s,Course c where s.c#=c.c# andc.cname in('Java编程思想','Struts2基础','Spring基础')
groupby s.s#
orderbyround(avg(s.score),2)desc;
--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 s.c# as课程ID,max(s.score)as最高分,min(s.score)as最低分
from SC s
groupby s.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 s.c# as课程ID,round(avg(s.score),2)as平均分,
round(100*sum(casewhen s.score>=60then1else0end)/count(s.score),0)||'%'as及格率
from SC s
groupby s.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)
selectround(sum(casewhen c.cname='Java编程思想'then s.score else0end)/sum(case c.cnamewhen'Java编程思想'then1else0end),2)as Java编程思想,
round(100*sum(casewhen s.score>=60and c.cname='Java编程思想'then1else0end)/sum(casewhen c.cname='Java编程思想'then1else0end),0)||'%'as及格率,
round(sum(casewhen c.cname='Struts2基础'then s.scoreelse0end)/sum(case c.cnamewhen'Struts2基础'then1else0end),2)as Struts2基础,
round(100*sum(casewhen s.score>=60and c.cname='Struts2基础'then1else0end)/sum(casewhen c.cname='Struts2基础'then1else0end),0)||'%'as及格率
from SC s,Course c
where s.c#=c.c#;
--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
select t.t# as教师ID,
max(t.tname)as教师名称,
c.cname as所教课程,
round(avg(s.score),2)as平均分
from Teacher t, Coursec, SC s
where t.t# = c.t# and c.c# = s.c#
groupby t.t#, c.cname
orderby t.t#,round(avg(s.score),2)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)
select d.s#,d.sname,c.cname,s.score,s.rank1 as名次
from Student d,Course c,
(select s#,c#,score,row_number()over(partitionby c# orderby score desc) rank1 from SC) s
where s.c#=c.c# and d.s#=s.s#
and c.cnamein('Java编程思想','Struts2基础','Hibernate基础','Spring基础')
and(s.rank1 between3and6)
orderby c.c#,s.rank1;
--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 s.c#,max(c.cname),
sum(casewhen s.scorebetween85and100then1else0end)as分数85至100,
sum(casewhen s.scorebetween70and85then1else0end)as分数70至85,
sum(casewhen s.scorebetween60and70then1else0end)as分数60至70,
sum(casewhen s.scorebetween0and60then1else0end)as小于60
from SC s,Course c
where s.c#=c.c#
groupby s.c#;
--24、查询学生平均成绩及其名次
select d.s#,max(d.sname),round(avg(s.score),2)as平均分,
dense_rank()over(orderbyavg(s.score)desc)as名次
from Student d,SC s
where d.s#=s.s#
groupby d.s#;
--25、查询各科成绩前三名的记录:(不考虑成绩并列情况)
select c.c# as课程编号,c.cname as课程名称,
d.sname as学生名称,s.rank1 as名次,s.score as成绩
from(select s#,c#,score,
row_number()over(partitionby c# orderby score desc) rank1
from sc ) s,Course c,Studentd
where s.c#=c.c# and s.s#=d.s# and rank1 <4
orderby c.c#,s.rank1;
--26、查询每门课程被选修的学生数
select s.c#,count(distinct s.s#)as人数
from SC s
groupby s.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 d.s#,max(d.sname)
from SC s,Studentd
where d.s#=s.s#
groupby d.s#
havingcount(distinct s.c#)=1;
--28、查询男生、女生人数
selectsum(case d.ssex when'男'then1else0end)as男生,
sum(case d.ssex when'女'then1else0end)as女生
from Student d;
--29、查询姓“张”的学生名单
select*
from Student d
where d.sname like'张%';
--30、查询同名同性学生名单,并统计同名人数
select d.sname,d.ssex,count(0)
from Student d
groupby d.sname,d.ssex
havingcount(0)>1;
--31、1981年出生的学生名单(注:Student表中Sage列的类型是datetime)
select*
from Student d
where to_char(d.sage,'yyyy')='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 s.c#,round(avg(s.score),2)as平均分
from SC s
groupby s.c#
orderbyavg(s.score),s.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 s.s#,max(d.sname),round(avg(s.score),2)as平均分
from SC s,Studentd
where s.s#=d.s#
groupby s.s#
havingavg(s.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 d.sname,s.score
from Student d,SC s,Course c
where d.s#=s.s# and s.c#=c.c# and c.cname='Java编程思想'and s.score<60;
--35、查询所有学生的选课情况;
select d.s#,max(d.sname),count(distinct s.c#)as选课数
from Student d leftjoin SC s on(d.s#=s.s#)
groupby d.s#;
--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;
selectmax(d.sname),max(c.cname),s.score
from Student d,SC s,Course c
where d.s#=s.s# and s.c#=c.c# and s.score>70
groupby s.s#,s.score
havingcount(0)=(selectcount(s1.c#)from SC s1 where s.s#=s1.s#);
--37、查询不及格的课程,并按课程号从大到小排列
select s.s#,c.cname,s.score
from SC s,Course c
where s.c#=c.c# and s.score<60
orderby s.c# desc;
--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 d.s#,d.sname
from Student d,SC s
where d.s#=s.s# and s.c#='003'and s.score>80;
--39、求选了课程的学生人数
selectcount(distinct s.s#)as选课的人数
from SC s;
--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 sname,score
from(select d.sname,s.score,row_number()over(orderby s.scoredesc)as rank1
from Studentd,SC s,Course c,Teachert
where d.s#=s.s# and s.c#=c.c# and c.t#=t.t# and t.tname='叶平')
where rank1=1;
--41、查询各个课程及相应的选修人数
select s.c#,count(distinct s.s#)as选修人数
from SC s
groupby s.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*
from SC s1,SC s2
where s1.c#<>s2.c# ands1.score=s2.score and s1.s#<>s2.s#;
--43、查询每门功成绩最好的前两名
select d.s#,d.sname,s.c#,s.score,s.rank1
from(select s1.s#,s1.c#,s1.score,
row_number()over(partitionby s1.c# orderbys1.score desc)as rank1
from SC s1) s,Studentd
where s.s#=d.s# and rank1 <3
orderby s.c#,s.rank1;
--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 s.c#,count(distinct s.s#)as选修人数
from Course c leftjoin SC s on(c.c#=s.c#)
groupby s.c# havingcount(distinct s.s#)>10
orderbycount(distinct s.s#)desc,s.c#;
--45、检索至少选修两门课程的学生学号
select s.s#
from SC s
groupby s.s#
havingcount(distinct s.c#)>=2;
--46、查询全部学生都选修的课程的课程号和课程名
select s.c# as课程编号,
max(c.cname)as课程名称
from SC s,Course c
where s.c#=c.c#
groupby s.c#
havingcount(distinct s.s#)=(selectcount(0)from Student);
--47、查询没学过“叶平”老师讲授的任一门课程的学生姓名
select d.s#,d.sname
from Student d
wherenotexists(select s.s# from SC s,Course c,Teachert
where s.c#=c.c# and c.t#=t.t# and s.s#=d.s# and t.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.s#,round(avg(s.score),2)as平均分
from SC s where s.score<60
groupby s.s#
havingcount(s.c#)>2;
--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.s#
from SC s where s.c#='004'and s.score<60
orderby s.scoredesc;
--50、删除“1002”同学的“001”课程的成绩
deletefrom SC s
where s.s#='1002'and s.c#='001';