ALTER VIEW

ALTER VIEW is used to alter an existing view.

Description

ALTER VIEW is used to alter an existing view.

If any of the views named in the syntax parameter list do not exist, the statement reports an error and cannot change those views that do not exist.

Starting with v3.0.11, ALTER VIEW accepts an optional SQL SECURITY clause that replaces the view's stored security type. See CREATE VIEW for the meaning of DEFINER and INVOKER. If the clause is omitted, the stored security type is recomputed from the current session variable view_security_type.

Syntax

> ALTER [SQL SECURITY { DEFINER | INVOKER }] VIEW view_name [(column_list)]
  AS select_statement
  [WITH [CASCADED | LOCAL] CHECK OPTION]

Examples

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)