sql中的视图设计

sql中的视图设计

-- or REPLACE 检查视图是否重复 替换
CREATE or REPLACE view view01
as
SELECT d.DEPTNO as d,e.EMPNO as o , d.loc,d.DNAME,e.ENAME,e.job,e.SAL
from 
emp e
​
-- 创建基于视图的视图：
create or replace view myview04
as
select * from myview03 where deptno = 20;
select * from myview04;