use student_class
create table Student
(
sclass varchar(2),--班級
sno varchar(2),--學號
sname varchar(10) not null,--姓名
ssex varchar(2) check(ssex in('男','女')),--性別,將性別限制為男女
sage int ,--年齡
sdept varchar(5),--系別
primary key(sno,sclass)
)
insert into Student(sclass,sno,sname,ssex,sage,sdept)
values(1,1,'李勇','男',20 ,'IS') 
insert into Student(sclass,sno,sname,ssex,sage,sdept)
values(1,2,'劉晨','女',19 ,'IS') 
insert into Student(sclass,sno,sname,ssex,sage,sdept)
values(1,3,'劉朋','男',20 ,'IS') 
insert into Student(sclass,sno,sname,ssex,sage,sdept)
values(2,1,'王敏','女',18 ,'MA') 
insert into Student(sclass,sno,sname,ssex,sage,sdept)
values(2,2,'張鋒','男',19 ,'MA') 
insert into Student(sclass,sno,sname,ssex,sage,sdept)
values(2,3,'李敏','男',20 ,'MA')