Jan 092009
If you need to assign an orphan user in MS SQL 2005 – meaning a user without a log in – to a new login, or change the login for a user, simply run the following query:
ALTER USER <userName> WITH login = <loginName>
on the database.
This is a problem which can happen if you for example restore databases to a new server, where you have a user in the database, but no mapped login.