1.新建表 test

id varchar2(20)
name varchar2(20)
addr varchar2(50)
score number

create table test
(id varchar2(20),
name varchar2(20),
addr varchar2(50),
score number
)

2.給id增加主鍵約束
alter table test add constraint pk_id primary key(id)
3.查詢出分數大於60分的人員，並按分數降序進行排列

select * from test where score>60 order by score desc
4.新增數據 001 zhangsan shenzhen 80

6. 將zhangsan的分數修改成60
   update test set score=60 where name=‘zhangsan‘

7.刪除zhangsan的信息

delete from test where name=‘zhangsan‘

二、

Student(S#,Sname,Sage,Ssex) 學生表
Course(C#,Cname,T#) 課程表
SC(S#,C#,score) 成績表
Teacher(T#,Tname) 教師表

問題：

1、查詢平均成績大於60分的同學的學號和平均成績； avg

select s#,avg(score) from sc where (select avg(score) from sc)>60 group by s# ;

select s#,avg(score) from sc where group by s# having avg(score)>60;

2、查詢所有同學的學號、姓名、選課數、總成績；

select Student.s#,sname,count(C#),sum(score) from Student inner join sc on Student.s#=sc.s# group by Student.s#,sname

3、查詢姓“李”的老師的個數；

select count(*) from teacher where tname like‘李%‘

4、查詢沒學過“葉平”老師課的同學的學號、姓名；

select S#,Sname from Student where s# in (select S# from sc where c# not in (select c# from Course where T#=(select T# from teacher where Tname=‘葉平‘ ))

5、查詢所有課程成績小於60分的同學的學號、姓名；

select S#,Sname from Student where s# not in (select S# from sc where score>60)

軟件測試-常見數據庫筆試題