create database DB
use DB
--专业表
create table major
(spno char(5) not null primary key,
spname varchar(20) not null,
pno char(2) )
--学生表
create table student
(sno char(7) not null primary key,
sname varchar(20) not null,
ssex char(2) not null,
sage smalldatetime,
spno char(5) not null foreign key references major(spno),
classid char(5),
Inyear char(4) not null )
select datediff(yyyy,'1981-8-12',getdate())from student
--课程表
create table course
(cno char(10) not null primary key,
cname varchar(20) not null,
credit smallint,
tno char(3))
--选课表
create table scourse
(sno char(7) not null foreign key references student(sno),
cno char(10) not null foreign key references course(cno),
Gmark numeric(4,1),
primary key(sno,cno))
//第一题
select * from student where datediff(yyyy,sage,getdate()) between 25 and (select datediff(yyyy,getdate()) from student where sname='李勇')
//第二题
select sno,sname from student where sno in ( select sno from scourse where cno=(select cno from course where cname='操作系统'))
//第三题
select sname from student where sno in (select distinct sno from scourse where cno not in('1'))
//第四题
select sname,sno from student where sno in(select sno from scourse group by sno having count(sno)=(select count(*) from course))
select student.sname,student.sno from student where student.sno in(select scourse.sno from scourse group by scourse.sno having count(scourse.sno)=(select count(*) from course))
//第五题
select sname from student where sno in (select sno from student where Inyear='1999') and sno in (select sno from scourse where Gmark is null) and spno in(select spno from major where spname='计算机软件')
select student.sname from student where student.sno in (select student.sno from student where student.Inyear='1999') and student.sno in (select scourse.sno from scourse where scourse.Gmark is null) and student.spno in(select major.spno from major where major.spname='计算机软件')
