Removing orphaned users from a SQLServer database18 Oct 2014
If you are using SQLServer probably you had to restore a database from a backup and got stuck with an orphaned user that was no more associated with a login.
Microsoft provides a stored procedure to remove this orphaned user:
You could get an error because the user still owns a schema. To find out which schema is bound with the user you can use this query
And then drop the orphaned user from the schema