> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/reference/sql-commands/sql-alterview.md).

# ALTER VIEW

### ALTER VIEW

ALTER VIEW — change the definition of a view

### Synopsis

```

ALTER VIEW [ IF EXISTS ] name ALTER [ COLUMN ] column_name SET DEFAULT expression
ALTER VIEW [ IF EXISTS ] name ALTER [ COLUMN ] column_name DROP DEFAULT
ALTER VIEW [ IF EXISTS ] name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER VIEW [ IF EXISTS ] name RENAME [ COLUMN ] column_name TO new_column_name
ALTER VIEW [ IF EXISTS ] name RENAME TO new_name
ALTER VIEW [ IF EXISTS ] name SET SCHEMA new_schema
ALTER VIEW [ IF EXISTS ] name SET ( view_option_name [= view_option_value] [, ... ] )
ALTER VIEW [ IF EXISTS ] name RESET ( view_option_name [, ... ] )
```

### Description

`ALTER VIEW` changes various auxiliary properties of a view. (If you want to modify the view's defining query, use `CREATE OR REPLACE VIEW`.)

You must own the view to use `ALTER VIEW`. To change a view's schema, you must also have `CREATE` privilege on the new schema. To alter the owner, you must be able to `SET ROLE` to the new owning role, and that role must have `CREATE` privilege on the view's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the view. However, a superuser can alter ownership of any view anyway.)

### Parameters

*`name`* : The name (optionally schema-qualified) of an existing view.

*`column_name`* : Name of an existing column.

*`new_column_name`* : New name for an existing column.

`IF EXISTS` : Do not throw an error if the view does not exist. A notice is issued in this case.

`SET`/`DROP DEFAULT` : These forms set or remove the default value for a column. A view column's default value is substituted into any `INSERT` or `UPDATE` command whose target is the view, before applying any rules or triggers for the view. The view's default will therefore take precedence over any default values from underlying relations.

*`new_owner`* : The user name of the new owner of the view.

*`new_name`* : The new name for the view.

*`new_schema`* : The new schema for the view.

`SET ( view_option_name [= view_option_value] [, ... ] )`\
`RESET ( view_option_name [, ... ] )` : Sets or resets a view option. Currently supported options are:

```
`check_option` (`enum`)
:   Changes the check option of the view. The value must
    be `local` or `cascaded`.

`security_barrier` (`boolean`)
:   Changes the security-barrier property of the view. The value must
    be a Boolean value, such as `true`
    or `false`.

`security_invoker` (`boolean`)
:   Changes the security-invoker property of the view. The value must
    be a Boolean value, such as `true`
    or `false`.
```

### Notes

For historical reasons, `ALTER TABLE` can be used with views too; but the only variants of `ALTER TABLE` that are allowed with views are equivalent to the ones shown above.

### Examples

To rename the view `foo` to `bar`:

```

ALTER VIEW foo RENAME TO bar;
```

To attach a default column value to an updatable view:

```

CREATE TABLE base_table (id int, ts timestamptz);
CREATE VIEW a_view AS SELECT * FROM base_table;
ALTER VIEW a_view ALTER COLUMN ts SET DEFAULT now();
INSERT INTO base_table(id) VALUES(1);  -- ts will receive a NULL
INSERT INTO a_view(id) VALUES(2);  -- ts will receive the current time
```

### Compatibility

`ALTER VIEW` is a PostgreSQL extension of the SQL standard.

### See Also

[CREATE VIEW](/reference/sql-commands/sql-createview.md), [DROP VIEW](/reference/sql-commands/sql-dropview.md)

***

原文：[PostgreSQL 18.6 Documentation](https://www.postgresql.org/docs/18/sql-alterview.html)（英文原文，待翻譯）


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