create table student(
sno char(4) not null,
sname char(10) not null,
dname char (10) not null,
ssex char(2),
cno int,
mark decimal(3,1),
type char(4)
)
insert into student values('9701','刘建国','管理工程','男',4,82.5,'必修')
insert into student values('9701','刘建国','管理工程','男',10,70,'选修')
insert into student values('9701','刘建国','管理工程','男',1,78.5,'选修')
insert into student values('9702','李春','环境工程','女',5,63,'必修')
insert into student values('9702','李春','环境工程','女',10,58,'选修')
insert into student values('9703','王天','生物','男',5,48.5,'必修')
insert into student values('9703','王天','生物','男',2,86,'选修')
insert into student values('9704','李华','计算机','女',4,76,'必修')
insert into student values('9704','李华','计算机','女',1,92,'必修')
insert into student values('9704','李华','计算机','女',2,89,'必修')
insert into student values('9704','李华','计算机','女',9,80,'必修')