create table student(
sno varchar2(10) primary key,
sname varchar2(20),
sage number(2),
ssex varchar2(5)
);
create table teacher(
tno varchar2(10) primary key,
tname varchar2(20)
);
create table course(
cno varchar2(10),
cname varchar2(20),
tno varchar2(20),
constraint pk_course primary key (cno,tno)
);
create table sc(
sno varchar2(10),
cno varchar2(10),
score number(4,2),
constraint pk_sc primary key (sno,cno)
);
/*******初始化学生表的数据******/
insert into student values (\'s001\',\'张三\',23,\'男\');
insert into student values (\'s002\',\'李四\',23,\'男\');
insert into student values (\'s003\',\'吴鹏\',25,\'男\');
insert into student values (\'s004\',\'琴沁\',20,\'女\');
insert into student values (\'s005\',\'王丽\',20,\'女\');
insert into student values (\'s006\',\'李波\',21,\'男\');
insert into student values (\'s007\',\'刘玉\',21,\'男\');
insert into student values (\'s008\',\'萧蓉\',21,\'女\');
insert into student values (\'s009\',\'陈萧晓\',23,\'女\');
insert into student values (\'s010\',\'陈美\',22,\'女\');
commit;
/******************初始化教师表***********************/
insert into teacher values (\'t001\', \'刘阳\');
insert into teacher values (\'t002\', \'谌燕\');
insert into teacher values (\'t003\', \'胡明星\');
commit;
/***************初始化课程表****************************/
insert into course values (\'c001\',\'J2SE\',\'t002\');
insert into course values (\'c002\',\'Java Web\',\'t002\');
insert into course values (\'c003\',\'SSH\',\'t001\');
insert into course values (\'c004\',\'Oracle\',\'t001\');
insert into course values (\'c005\',\'SQL SERVER 2005\',\'t003\');
insert into course values (\'c006\',\'C#\',\'t003\');
insert into course values (\'c007\',\'JavaScript\',\'t002\');
insert into course values (\'c008\',\'DIV+CSS\',\'t001\');
insert into course values (\'c009\',\'PHP\',\'t003\');
insert into course values (\'c010\',\'EJB3.0\',\'t002\');
commit;
/***************初始化成绩表***********************/
insert into sc values (\'s001\',\'c001\',78.9);
insert into sc values (\'s002\',\'c001\',80.9);
insert into sc values (\'s003\',\'c001\',81.9);
insert into sc values (\'s004\',\'c001\',60.9);
insert into sc values (\'s001\',\'c002\',82.9);
insert into sc values (\'s002\',\'c002\',72.9);
insert into sc values (\'s003\',\'c002\',81.9);
insert into sc values (\'s001\',\'c003\',\'59\');
commit;
试题：
1、查询“c001”课程比“c002”课程成绩高的所有学生的学号；
sql> select a.sno from (select * from sc a where a.cno=\'c001\') a, (select * from sc b where b.cno=\'c002\') b where a.sno=b.sno and a.score > b.score;
sql>select * from sc a where a.cno=\'c001\' and exists(select * from sc b where b.cno=\'c002\' and 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；
sql>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；
sql>select a.*,student.sname from (select sno, count(cno),sum(score) from sc group by sno) a,student b where a.sno=b.sno;
sql> select sc.sno, student.sname,sum(score),count(cno) from sc,student where sc.sno=student.sno group by sc.sno,student.sname;
4、查询姓“刘”的老师的个数；
sql> select count(tno) from teacher where tname like ‘刘%’;
5、查询没学过“谌燕”老师课的同学的学号、姓名；
sql> select a.sno,a.sname from student a where a.sno not in (select distinct s.sno from sc s join course c on s.cno=c.cno join teacher t on c.tno=t.tno where tname=’胡燕;)
sql> select a.sno,a.sname from student a where a.sno not in (select distinct s.sno from sc s, (select c.* from course c , (select tno from teacher t where tname=\'谌燕\') t where c.tno=t.tno) b where s.cno = b.cno );
sql> select sc.sno,student.sname from student, teacher, course, sc where teacher.tname is not \'谌燕\' and teacher.tno = course.tno and course.cno = sc.cno and sc.sno = student.sno;
6、查询学过“c001”并且也学过编号“c002”课程的同学的学号、姓名；
sql> select st.* from sc a join sc b on a.sno=b.sno join student st on st.sno=a.sno where a.cno=\'c001\' and b.cno=\'c002\' and st.sno=a.sno;
sql> select sc.sno,student.sname from sc,student where sc.cno=’c001’ and sc.cno in (select sno from sc where cno=’c002’);
7、查询学过“谌燕”老师所教的所有课的同学的学号、姓名；
sql> select st.* from student st join sc s on st.sno=s.sno join course c on s.cno=c.cno join teacher t on c.tno=t.tno where t.tname=‘谌燕’;
8、查询课程编号“c002”的成绩比课程编号“c001”课程低的所有同学的学号、姓名；
sql> select * from student st join sc a on st.sno=a.sno join sc b on st.sno=b.sno where a.cno=\'c002\' and b.cno=\'c001\' and a.score < b.score;
sql> select sc.sno,student.sname from sc,student where sc.sno=student.sno and sc.cno=’c002’ and sc.score<any(select score from sc where cno=’c001’);
9、查询所有课程成绩小于60 分的同学的学号、姓名；
sql> select st.*,s.score from student st join sc s on st.sno=s.sno join course c on s.cno=c.cno where s.score <60;
sql> select sc.sno,student.sname from sc,student where sc.sno=student.sno and sc.score < 60;
10、查询没有学全所有课的同学的学号、姓名；
sql> select stu.sno,stu.sname,count(sc.cno) from student stu left join sc on stu.sno=sc.sno group by stu.sno,stu.sname having count(sc.cno)<(select count(distinct cno)from course);
sql> select * from student where sno in (select sno from (select stu.sno,c.cno from student stu cross join course c minus select sno,cno from sc));
sql> select sno from student intersect (select sno from (select stu.sno,c.cno from student stu cross join course c minus select sno,cno from sc));
11、查询至少有一门课与学号为“s001”的同学所学相同的同学的学号和姓名；
sql> select st.* from student st, (select distinct a.sno from (select * from sc) a, (select * from sc where sc.sno=\'s001\') b where a.cno=b.cno) h where st.sno=h.sno and st.sno<>\'s001\';
12、查询至少学过学号为“s001”同学所有一门课的其他同学学号和姓名；
sql> select * from sc left join student st on st.sno=sc.sno where sc.sno<>\'s001\' and sc.cno in (select cno from sc where sno=\'s001\');
13、把“SC”表中“谌燕”老师教的课的成绩都更改为此课程的平均成绩；
sql> update sc c set score=(select avg(c.score) from course a,teacher b where a.tno=b.tno and b.tname=\'谌燕\' and a.cno=c.cno group by c.cno) where cno in(select cno from course a,teacher b where a.tno=b.tno and b.tname=\'谌燕\');
14、查询和“s001”号的同学学习的课程完全相同的其他同学学号和姓名；
sql> select* from sc where sno<>\'s001 minus (select* from sc minus select * from sc where sno=\'s001\');
15、删除学习“谌燕”老师课的SC 表记录；
sql> delete from sc where sc.cno in (select cno from course c left join teacher t on c.tno=t.tno where t.tname=\'谌燕\');
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“c002”课程的同学学号、“c002”号课的平均成绩；
sql> insert into sc (sno,cno,score) select distinct st.sno,sc.cno,(select avg(score)from sc where cno=\'c002\') from student st,sc where not exists (select * from sc where cno=\'c002\' and sc.sno=st.sno) and sc.cno=\'c002\';
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
sql> select cno ,max(score),min(score) from sc group by cno;
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
sql> select cno,avg(score),sum(case when score>=60 then 1 else 0 end)/count(*) as ‘及格率’ from sc group by cno order by avg(score) , ‘及格率’desc;
19、查询不同老师所教不同课程平均分从高到低显示
sql> select max(t.tno),max(t.tname),max(c.cno),max(c.cname),c.cno,avg(score) from sc , course c,teacher t where sc.cno=c.cno and c.tno=t.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]
sql> select sc.cno,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 "[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 c where sc.cno=c.cno group by sc.cno ,c.cname;
21、查询各科成绩前三名的记录:(不考虑成绩并列情况)
sql> select * from (select sno,cno,score,row_number()over(partition by cno order by score desc) rn from sc) where rn<4;
22、查询每门课程被选修的学生数
sql> 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
sql> select sc.sno,st.sname,count(cno) from student st left join sc on sc.sno=st.sno group by st.sname,sc.sno having count(cno)=1;
24、查询男生、女生人数
sql> select ssex,count(*)from student group by ssex;
25、查询姓“张”的学生名单
sql> select * from student where sname like \'张%\';
26、查询同名同性学生名单，并统计同名人数
sql> 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number)
sql> select sno,sname,sage,ssex from student t where to_char(sysdate,\'yyyy\')-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
sql> select cno,avg(score) from sc group by cno order by avg(score)asc,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
sql> select st.sno,st.sname,avg(score) from student st left join sc on sc.sno=st.sno group by st.sno,st.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
sql> select sname,score from student st,sc,course c where st.sno=sc.sno and sc.cno=c.cno and c.cname=\'Oracle\' and sc.score<60;
31、查询所有学生的选课情况；
sql> select st.sno,st.sname,c.cname from student st,sc,course c where sc.sno=st.sno and sc.cno=c.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；
sql> select st.sname,c.cname,sc.score from student st,sc,course c where sc.sno=st.sno and sc.cno=c.cno and sc.score>70;
33、查询不及格的课程，并按课程号从大到小排列
sql> select sc.sno,c.cname,sc.score from sc,course c where sc.cno=c.cno and sc.score<60 order by sc.cno desc;
34、查询课程编号为c001 且课程成绩在80 分以上的学生的学号和姓名；
sql> select st.sno,st.sname,sc.score from sc,student st where sc.sno=st.sno and cno=\'c001\' and score>80;
35、查询选了课程的学生人数
sql> select count(distinct sno) from sc;
36、查询选修“谌燕”老师所授课程的学生中，成绩最高的学生姓名及其成绩
sql> select st.sname,score from student st,sc ,course c,teacher t where st.sno=sc.sno and sc.cno=c.cno and c.tno=t.tno and t.tname=\'谌燕\' and sc.score= (select max(score)from sc where sc.cno=c.cno);
37、查询各个课程及相应的选修人数
sql> select cno,count(sno) 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
sql> select a.* from sc a ,sc b where a.score=b.score and a.cno<>b.cno;
39、查询每门功课成绩最好的前两名
sql> select * from (select sno,cno,score,row_number()over(partition by cno order by score desc) my_rn from sc t ) where my_rn<=2;
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，若人数相同，按课程号升序排列
sql> select cno,count(sno) from sc group by cno having count(sno)>10 order by count(sno) desc,cno asc;
41、检索至少选修两门课程的学生学号
sql> select sno from sc group by sno having count(cno)>1;
42、查询全部学生都选修的课程的课程号和课程名
sql> select distinct(c.cno),c.cname from course c ,sc where sc.cno=c.cno || select cno,cname from course c where c.cno in (select cno from sc group by cno);
43、查询没学过“谌燕”老师讲授的任一门课程的学生姓名
sql> select st.sname from student st where st.sno not in (select distinct sc.sno from sc,course c,teacher t where sc.cno=c.cno and c.tno=t.tno and t.tname=\'谌燕\')\';
44、查询两门以上不及格课程的同学的学号及其平均成绩
sql> select sno,avg(score)from sc where sno in (select sno from sc where sc.score<60 group by sno having count(sno)>1) group by sno;
45、检索“c004”课程分数小于60，按分数降序排列的同学学号
sql> select sno from sc where cno=\'c004\' and score<90 order by score desc;
46、删除“s002”同学的“c001”课程的成绩
sql> delete from sc where sno=\'s002\' and cno=\'c001\';