I have a user who was inserted into the db by one of our automation scripts. His ID has the very first letter capitalized. The script reads the users from the appropriate Active Directory group and makes sure they exist in the database.
For grins, let's say the user is good old Charley Brown and is called "Cbrown1" in Active Directory. If I look for him by rolname in either pg_authid or the pg_roles view, He shows as:
rolname -----------
Cbrown1
(1 row)
but when I try then to get rid of him using either "DROP ROLE cbrown1;" or "DROP ROLE Cbrown1;" I receive "ERROR: role "cbrown1" does not exist. Note that I get the error with the name in all lower case regardless of which way I specify him.
Also, he does not show up using \du Cbrown1 or \du+ cbrown1, but does show if I enter \du without specifying his id.