It's not a bad question. In this industry most drug tests are random anyway. Could you imagine if they tested for alcohol? They would probably lose half the work force. Just play by the rules and you'll be fine. Most companies require 12 hours before any company event and less than .04 BAC. It's OK to enjoy a couple of beers here and there, just don't abuse the privilege.
Be careful they do test for cigarettes.
They do test for alcohol. I've been tested twice at duty in.