I was working with a customer to figure out how many different variations of computer memory card slots they had in the environment. Turns out there are many (DIMM A, DIMM_A, Slot 1, Slot_1, Top Slot, Bottom Slot, etc). The query is a very specific use case but putting it here in case it helps you out. If nothing else it's a sample on how to do counts.
SELECT DISTINCT COUNT(DeviceLocator0) DeviceLocator0
GROUP BY DeviceLocator0