In the database, different regions are identified by a region number. I have a long, complicated query and what I'd like to do is use a variable for the region number. That way if I want to run the query for a different region, I can change the region number in just one place instead of 5 places scattered throughout the query.

I've tried a few things based on examples I found online but I just can't get it to work for some reason. Help!