题目描述：针对actor表创建视图actor_name_view，只包含first_name以及last_name两列，并对这两列重新命名，first_name为first_name_v，last_name修改为last_name_v

两种写法：
1.直接在视图名的后面用小括号创建视图中的字段名

create view actor_name_view (first_name_v,last_name_v) as
select first_name ,last_name from actor

2.在select后面对列重命名为视图的字段名

create view actor_name_view as
select first_name as first_name_v
       ,last_name as last_name_v
from actor