sales DB selecting column and column range

[pher77]

I am creating a DB that contains sales data and is structured as such


an_UPC_ID, str_UPC_Description, 1 week sales ending ######
The one week slices of date start Feb 1, 2009 and continue till the end of 2012.
Is there a way to create a query that will select the last column that is NOT NULL?
I am also trying to find a way to create a range of 13, 26 and 52 weeks from the most current which would be the last column with a NOT Null results.
Or should I structure my table differently?

Any help and suggestions are much appreciated

[pbaldy]

Your data is not normalized, and will likely be a nightmare to work with. I would expect fields like

an_UPC_ID
str_UPC_Description
SalesDate
Amount

A UPC with 10 weeks of data would have 10 records in this table. When you got the 11th week's data, you'd add a record with that date. From there, it would be fairly easy to query the data for the ranges you describe. More on normalization here:

Fundamentals of Relational Database Design -- r937.com

[pher77]

Paul,
my upc list is already at 6500 skus and will continue to grow. I already hold 125 weeks of sales with another 75 or so to go. will laying a new table out this way become an issue? i import 13 weeks of data at a time

thank you for your help

[pbaldy]

I don't think that's an unmanageable amount of data for Access. I'd certainly try it.