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回答时间:2024-04-29 19:33
一、create table student (
sno char(9) primary key,
sname char(10) not null,
ssex char(2) default '男',
sage smallint,
sdep char(20)
)
二、
1.select * from student;
2.alter tatble student add ‘年级’ char(4);
3.modify student set sname char(20);
4.alter table student drop column '年级';
三、
1.insert into student values('201215128','陈冬',‘男’,18,‘信息系’);
2.update student set sage=22 where sno = '201215121';
3.delete from student where sname='张立'
四、
1.select * from student;
2.select sname,ssex from student;
4.select sname,sdep from student group by sname;
5.select * from student where rownum <=5
6.select * from student where ssex='女'
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