(a precursory search didn't turn anything up, so hoping someone has an idea)
I need to do a rolling 90 day sum of sales on a dataset. There are a few conditions to this:
1) there is a field (model) I will be grouping by
2) if a particular model is not sold on a given day, there will be no record in the data.
Attached is the simplest solution I could think of that would cover all the options. I didn't want to write a multi-row formula with 90 rows as changing it later would be a pain and what's the fun in that, so this was my alternative. My fear is that this solution could get quite large, but after a date is 90 days past, my total does not change so after an initial run I can 'archive' a set of dates and append new dates as new data comes in.
I'm guessing there's a more direct way to accomplish this, but I'm unsure as to what. Any simpler ideas?
