Set analysis and two dates Fields

[#1]

Hi,

I've got in my module,

the following tables:

Item Table:

Item,

Date

Sales:

Item,

SaleDate,

Qty

I need to calculate for each item sum(Qty) where SaleDate<= Date.

I know set analysis back and forward but somehow i can't manage to do that.

Can someone know how to solve this issue?

Thnx a lot

[#2]

Thanks for the help,

but I've got two date fields, so i need to compare them without variables

[#3]

I understand.

So your expression would be: sum({<SalesDate = {"<=Date"}>}Qty)

[#4]

You cannot compare two different fields in set analysis. You have to use if.

[#5]

tried it and similar ups and down without a success

[#6]

Does anyone knows how to deal the issue in the script itself?

mainly because user perfomance