I'm stumped on this one and it seems simple enough but it just isn't working. I've tried using an if statement with no luck either. I don't care which as long as it works.
WHERE ti.TheatreId in
(CASE WHEN @Group = 'Amstar' THEN ('1562', '1564', '1565', '1566', '1567', '1568', '1569', '1570')...