Sum if between 2 dates

[thebigJLT]

I'm creating a basic inventory app. I want to add the ability to track the usage per month of each of the 5 items I am inventorying and display this as a table. 

I have a form set up to log the use of items which updates the total inventory, but I cannot figure out how to count the items, by their item number and by the month the depletion was logged. 

[TeeSee1]

Set up a child table to the inventory table, which I assume has the item field either as its key or a ref to a separate items table.

The child table should have the following fields

• id -> UNIQUEID()
• ref to the parent table
• year -> 4 digit number
• month -> ENUM of numbers from 1 to 12
• VC - monthly consumption with 

  SUM(
   SELECT(
    log[used qty], 
    AND(
     YEAR([log date]) = [_THISROW].[year], 
     MONTH([log date] = [_THISROW].[month], 
     [item]=[_THISROW].[ref to parent].[item] //if the inventory table's key is tbe item, then [_THISROW].[ref to parent] should be sufficient
    )
   )
  )