I'm struggling with an interview question. 3 dimension tables (Product, Store and Date) and 1 fact table (Sales). The question asks for a T-SQL solution that will return the count of products not sold, per store, per day over the past month. At this point, my answer is futile but I've spent significant time trying to back into a solution, to no avail, and would like to close the loop. Any guidance is greatly appreciated.