【摘要】 山东大学数据库实验6-2021年最新版
6-1create view test6_01 as
select sid,name,dname
from pub.student
where dname=’物理学院’and age<20
order by sid;6-2
create view test6_02 as
select sid,name,sum(scor…
山东大学数据库实验6-2021年最新版
6-1
create view test6_01 as
select sid,name,dname
from pub.student
where dname='物理学院'and age<20
order by sid;
6-2
create view test6_02 as
select sid,name,sum(score) sum_score
from pub.student left outer join pub.student_course using (sid)
where class=2009 and dname='软件学院'
group by sid,name;
6-3
create view test6_03 as
select sid,name,score
from pub.student natural join pub.student_course
where class=2010 and dname='计算机科学与技术学院' and cid =300005
;
6-4
create view test6_04 as
select sid,name
from pub.student natural join pub.student_course
where cid=300003 and score >90
;
6-5
create view test6_05 as
select sid,cid, name ,score
from pub.course natural join (
select sid,cid,score
from pub.student natural join pub.student_course
where name='李龙' )
;
6-6
create view test6_06 as
(select sid,name
from pub.student s
where not exists (
( select cid
from pub.course )
minus
( select cid
from pub.student_course t
where s.sid=t.sid )
));
注意:Oracle中使用MINUS代替except
6-7
create view test6_07 as
select sid,name,score
from test6_06 natural join pub.student_course
group by sid,name
having min(score)>=60;//保证了所有成绩都及格(如果只是score>=60,则代表只要有成绩大于等于60即可,但是不能保证所有成绩都大于等于60
6-8
create or replace view test6_08 as
select cid,name
from pub.course a
where exists ( select cid from pub.course where cid=a.fcid and credit=2 );
6-9
create or replace view test6_09 as
select sid,name,sum(sum_credit) sum_credit
from pub.student natural join(
select sid,sum(credit) sum_credit
from pub.student_course natural join pub.course
group by sid,cid
having max(score) >=60) //from子查询得到一个学生的及格的课程得到的学分
where class=2010 and dname='化学与化工学院'
group by sid;//所以要求学生的总学分应该把所有及格课程得到的学分加在一起,所以最外层应该再次做一个sum求和
6-10
create or replace view test6_10 as Select cid,name From pub.course a where exists( Select cid From pub.course b Where cid=a.fcid and exists( Select cid From pub.course Where cid=b.fcid) );
文章来源: blog.csdn.net,作者:weixin_47373497,版权归原作者所有,如需转载,请联系作者。
原文链接:blog.csdn.net/weixin_47373497/article/details/116839506
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