# **ALTER VIEW**

## **Grammar Description**

`ALTER VIEW` is used to change the view.

If the named view in the syntax parameter list does not exist, the statement reports an error: the view is invalid.

## **Grammar Structure**

```sql
ALTER VIEW view_name [(column_list)]
  AS select_statement
  [WITH [CASCADED | LOCAL] CHECK OPTION]
```

## **Example**

```text
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)
```