Need help regarding calculations involving different rows

[malaydash]

Hi everybody

I have a problem in access & am really stuck with it. I want to do some basic calculation (addition, subtraction etc..) between fields involving more than one rows. At present I am pretty comfortable writing expression in queries involving two or more columns. what I want is calculation involving two or more rows.

To elaborate a little more, suppose I got a table having date wise shipping details to various clients. And I want to know the difference between quantity shipped to a particular customer on two different date.(i.e- (Shipping qty on Date-1) - (Shipping qty on Date-2). Using a total query is giving me option to Sum, Count, Aggregate or Average the data but not the difference or comparison between two records.

A solution without using Visual Basic will be more help as VB is like Greek & Latin to me

Please help

 

[pbaldy]

How is it to know which dates you want to compare? Here's an example using vehicle mileages:

http://www.baldyweb.com/PrevValue.htm

 

[malaydash]

Thanks pbaldy

Hope this solves my problem. I will get back to you if I encounter any problem.

Anyway thanks a lot

 

[pbaldy]

Happy to help, and certainly post back if you get stuck.