ALTER VIEW

ALTER VIEW 用于更改视图。

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。

从 v3.0.13 开始，ALTER VIEW 支持可选的 SQL SECURITY 子句，用于更新视图元数据中保存的安全类型。DEFINER 与 INVOKER 的含义参见 CREATE VIEW。若未显式带该子句，MatrixOne 会以当前会话变量 view_security_type 的值重新写入视图的安全类型。

语法结构

> ALTER [SQL SECURITY { DEFINER | INVOKER }] 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)