--3

use test;
--自增(序列)
create table p(
 id int identity(1,1) primary key,
 name varchar(32),
);
insert into p(name)values('aaa');
select * from p where id=5;

--索引
--聚集/非聚集
--create index 索引名 on 表名(列名)；
create index index1_p on p(id);
--查询速度较快
--修改，插入，删除速度较慢，占用数据库空间多
create unique index index2_p on p(id);

drop index p.index1_p;
drop index p.index2_p;

--视图
create view view1
as
 select e.ename as 员工, e.job as 职位, m.ename as 上司, d.dname as 部门
  from emp e, emp m, dept d
  where e.manager = m.empno and e.deptno = d.deptno;

select * from view1;

drop view view1;
select * from view1;
select * from emp
update view1 set 职位='MANAGER' where 上司='KING';

drop view view1;

--游标
declare cur_emp scroll cursor
 for select * from emp order by empno;

select * from emp order by empno;
open cur_emp;
select * from emp order by empno;
select @@CURSOR_ROWS as '行数';
close cur_emp;