## Name

ALTER USER MAPPING — change the definition of a user mapping

## Synopsis

    ALTER USER MAPPING FOR { user_name | USER | CURRENT_USER | SESSION_USER | PUBLIC }
        SERVER server_name
        OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ] )

## Description

`ALTER USER MAPPING` changes the definition of a user mapping.

The owner of a foreign server can alter user mappings for that server for any user. Also, a user can alter a user mapping for his own user name if `USAGE` privilege on the server has been granted to the user.

## Parameters

`user_name`

  User name of the mapping. `CURRENT_USER` and `USER` match the name of the current user. `PUBLIC` is used to match all present and future user names in the system.

`server_name`

  Server name of the user mapping.

`OPTIONS ( [ ADD | SET | DROP ] `option` ['`value`'] [, ... ] )`

  Change options for the user mapping. The new options override any previously specified options. `ADD`, `SET`, and `DROP` specify the action to be performed. `ADD` is assumed if no operation is explicitly specified. Option names must be unique; options are also validated by the server's foreign-data wrapper.

## Examples

Change the password for user mapping `bob`, server `foo`:

    ALTER USER MAPPING FOR bob SERVER foo OPTIONS (SET password 'public');

## Compatibility

`ALTER USER MAPPING` conforms to ISO/IEC 9075-9 (SQL/MED). There is a subtle syntax issue: The standard omits the `FOR` key word. Since both `CREATE USER MAPPING` and `DROP USER MAPPING` use `FOR` in analogous positions, and IBM DB2 (being the other major SQL/MED implementation) also requires it for `ALTER USER MAPPING`, Postgres Pro diverges from the standard here in the interest of consistency and interoperability.

## See Also

CREATE USER MAPPING, DROP USER MAPPING