SQL Reference

ALTER USER MAPPING

The ALTER USER MAPPING statement is used to change the authorization ID or password that is used at a data source for a specified federated server authorization ID.

Invocation

This statement can be embedded in an application program or issued through the use of dynamic SQL statements. It is an executable statement that can be dynamically prepared. However, if the bind option DYNAMICRULES BIND applies, the statement cannot be dynamically prepared (SQLSTATE 42509).

Authorization

If the authorization ID of the statement is different than the authorization name that is mapped to the data source, then the authorization ID of the statement must include SYSADM or DBADM authority. Otherwise, if the authorization ID and the authorization name match, then no privileges or authorities are required.

Syntax

>>-ALTER USER MAPPING FOR----+-authorization-name-+------------->
                             '-USER---------------'
 
>-----SERVER--server-name--------------------------------------->
 
                  .-,--------------------------------------------------.
                  V   .-ADD--.                                         |
>-----OPTIONS--(----+-+------+---user-option-name--string-constant--+--+---)->
                    | '-SET--'                                      |
                    '-DROP--user-option-name------------------------'
 
>--------------------------------------------------------------><
 

Description

authorization-name

Specifies the authorization name under which a user or application connects to a federated database.

USER

The value in the special register USER. When USER is specified, then the authorization ID of the ALTER USER MAPPING statement will be mapped to the data source authorization ID that is specified in the REMOTE_AUTHID user option.

SERVER server-name

Identifies the data source accessible under the remote authorization ID that maps to the local authorization ID that's denoted by authorization-name or referenced by USER.

OPTIONS

Indicates what user options are to be enabled, reset, or dropped for the mapping that is being altered. Refer to User Options for descriptions of user-option-names and their settings.

ADD

Enables a user option.

SET

Changes the setting of a user option.

user-option-name

Names a user option that is to be enabled or reset.

string-constant

Specifies the setting for user-option-name as a character string constant.

DROP user-option-name

Drops a user option.

Notes

• A user option cannot be specified more than once in the same ALTER USER MAPPING statement (SQLSTATE 42853). When a user option is enabled, reset, or dropped, any other user options that are in use are not affected.
• A user mapping cannot be altered in a given unit of work (UOW) if the UOW already includes a SELECT statement that references a nickname for a table or view at the data source that is to be included in the mapping.

Examples

Example 1: Jim uses a local database to connect to an Oracle data source called ORACLE1. He accesses the local database under the authorization ID KLEEWEIN; KLEEWEIN maps to CORONA, the authorization ID under which he accesses ORACLE1. Jim is going to start accessing ORACLE1 under a new ID, JIMK. So KLEEWEIN now needs to map to JIMK.

   ALTER USER MAPPING FOR KLEEWEIN
      SERVER ORACLE1
      OPTIONS ( SET REMOTE_AUTHID 'JIMK' )   

Example 2: Mary uses a federated database to connect to a DB2 Universal Database for OS/390 data source called DORADO. She uses one authorization ID to access DB2 and another to access DORADO, and she has created a mapping between these two IDs. She has been using the same password with both IDs, but now decides to use a separate password, ZNYQ, with the ID for DORADO. Accordingly, she needs to map her federated database password to ZNYQ.

   ALTER USER MAPPING FOR MARY
      SERVER DORADO
      OPTIONS ( ADD REMOTE_PASSWORD 'ZNYQ' )