sp_change_users_login [@Action =] 'action' [,[@UserNamePattern =] 'user']
[,[@LoginName =] 'login']
[@Action =] 'action'
Describes the action to be performed by the procedure. action is varchar(10), and can be one of these values.
Links user entries in the sysusers table in the current database to logins of the same name in syslogins. It is recommended that the result from the Auto_Fix statement be checked to confirm that the links made are the intended outcome. Avoid using Auto_Fix in security-sensitive situations. Auto_Fix makes best estimates on links, possibly allowing a user more access permissions than intended.
user must be a valid user in the current database, and login must be NULL, a zero-length string, or not specified.
Lists the users, and their corresponding security identifiers (SID), that are in the current database, not linked to any login.
user and login must be NULL, a zero-length string, or not specified.
Links the specified user in the current database to login. login must already exist. user and login must be specified.
[@UserNamePattern =] 'user'
Is the name of a SQL Server user in the current database. user is sysname, with a default of NULL. sp_change_users_login can only be used with the security accounts of SQL Server logins and users; it cannot be used with Microsoft Windows users.
[@LoginName =] 'login'
Is the name of a SQL Server login. login is sysname, with a default of NULL.
Return Code Values
0 (success) or 1 (failure)
Any member of the public role can execute sp_change_users_login with the Report option. Only members of the sysadmin fixed server role can specify the Auto_Fix option. Only members of the sysadmin or db_owner roles can specify the Update_One option.
A. Show a report of the current user to login mappings
This example produces a report of the users in the current database and their security identifiers.
EXEC sp_change_users_login 'Report'
B. Change the login for a user
This example changes the link between user Mary in the pubs database and the existing login, to the new login NewMary (added with sp_addlogin).
–Add the new login.
EXEC sp_addlogin 'NewMary'
–Change the user account to link with the ‘NewMary’ login.
EXEC sp_change_users_login 'Update_One', 'Mary', 'NewMary'
Related Article: http://msdn2.microsoft.com/en-us/library/ms174378.aspx