ALTER VIEW
语法说明
ALTER VIEW 用于更改视图。
如果语法参数列表中命名的视图不存在,则语句报错:该视图无效。
语法结构
> ALTER VIEW view_name [(column_list)]
  AS select_statement
  [WITH [CASCADED | LOCAL] CHECK OPTION]
示例
drop table if exists t1;
create table t1 (a int);
insert into t1 values(1),(2),(3),(4);
create view v5 as select * from t1;
mysql> select * from v5;
+------+
| a    |
+------+
|    1 |
|    2 |
|    3 |
|    4 |
+------+
4 rows in set (0.01 sec)
alter view v5 as select * from t1 where a=1;
mysql> select * from v5;
+------+
| a    |
+------+
|    1 |
+------+
1 row in set (0.01 sec)
alter view v5 as select * from t1 where a > 2;
mysql> select * from v5;
+------+
| a    |
+------+
|    3 |
|    4 |
+------+
2 rows in set (0.00 sec)