Dave Bland shows how to figure out which database users tie back to which logins:
Over the years I have had to provide information about logins and database users, most of the time per a request of an auditor. Many times this is very easy to accomplish because the login name matches the name of the database user account. If you look at the “New User” screen you can see that I am able to enter a different User Name.
Because of this, I can have a User Name that doesn’t match the Login Name. From an audit perspective this can create some confusion. More importantly, it can make it difficult to provide accurate information to the auditors when asked.
Read on to see how you can tie these together even if the names don’t match.