Creating an inventory system - expiry dates

I am having issues counting and adding/subtracting from the inventory product list when dealing with the over the counter products.

  1. I would like to know how to count the items based on 2 criterias (name of product and expiry date) I would like that the quantities would be added together because they they have the same expiration day. ONLY FOR OTC CATEGORY. I have already calculated the other items.

Name of table [Receiving]

  1. After being able to count the items. Next, would be to add/subtract from the inventory table.
    Name of table [Products] based on the previous calculations.

Thanks for the help, I have been struggling for the past 2 days figuring out this problem.

I do not know where you are wanting this result to be, or when you want it to calculate, but you can calculate this total quantity with something like:

  Table[Quantity] ,
    [Expiry Date] = #another expiry date to compare against#
    [Product Name] = #another product name to compare against#

I don’t really understand what you’re wanting here. How do you expect to do this? Are you editing data directly? Are you adding in new records for using up items? Perhaps you need to review a typical inventory sample app?