Use CREATE USER MAPPING to define a user mapping for a foreign server - PolarDB

Maps a local database user to a foreign server, supplying the credentials that the foreign data wrapper uses to access an external data source.

Syntax

CREATE USER MAPPING [IF NOT EXISTS] FOR { user_name | USER | CURRENT_USER | PUBLIC }
    SERVER server_name
    [ OPTIONS ( option 'value' [ , ... ] ) ]

Usage notes

A user mapping stores the connection information — typically a username and password — that the foreign data wrapper combines with the foreign server definition to connect to an external data source.

Who can create a user mapping:

The owner of a foreign server can create a user mapping for any user.
If you have the USAGE privilege on a server, you can map your own username to that server.

Parameters

Parameter	Description
`IF NOT EXISTS`	Skips the command without raising an error if a mapping for the specified user and server already exists. Issues a notice instead. Note The existing mapping may not match what the command would have created.
`user_name`	The local database user to map. `CURRENT_USER` and `USER` resolve to the current session user. Specify `PUBLIC` to create a fallback mapping used when no user-specific mapping exists.
`server_name`	The foreign server to map the user to.
`OPTIONS ( option 'value' [, ... ] )`	Connection options for this mapping — typically the remote username and password. Option names must be unique. Valid option names and values depend on the foreign data wrapper for the server.

Examples

Map a named user to a server:

CREATE USER MAPPING FOR bob
    SERVER foo
    OPTIONS (user 'bob', password 'secret');

Map the current session user to a server:

CREATE USER MAPPING FOR CURRENT_USER
    SERVER production_db
    OPTIONS (user 'read_only_user', password 'secure_password');

What's next

ALTER USER MAPPING — modify an existing user mapping
DROP USER MAPPING — remove a user mapping
CREATE FOREIGN TABLE — define a foreign table that uses the server and user mapping