sqlserver 视图

/*drop table scourse
drop table course
drop table student
drop table major*/

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 )

--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))
/*（1）建立00312专业选修了001号课程的学生视图Stu_01312_1；
（2）建立00312专业选修了1号课程并且成绩不及格的学生视图Stu_00312_2；
（3）建立视图Stu_year，由学生学号、姓名、年龄组成；
（4）通过视图查询20岁以上的学生姓名；
（5）通过视图查询00312专业选修了1号课程并且成绩不及格的学生的学号、姓名、年龄。*/

//第一题
 drop view Stu_01312_1
 go
  create view Stu_01312_1 as select * from student where spno='00312' and sno in (select sno from scourse where cno='1')
 go
  select * from Stu_01312_1

//第二题
drop view Stu_00312_2
  go
  create view   Stu_00312_2 as select * from student where spno='00312'  and sno in(select sno from scourse where cno='1' and Gmark < 60)
 go
select * from Stu_00312_2

//第三题
 drop view Stu_00312_3
go
create view Stu_00312_3 as select sno,sname,sage from student
go

//第四题

select sname from Stu_00312_3 where sage >20

//第五题

select sno,sage from Stu_00312_2