Net count

[mirrorwatch]

Here is the scenario,

There are many items( For eg:"apple")

I can either buy or sell. But only 1 amount. So it means either I have the apple or do not the apple.

And then I have a table with all applications with dates of transactions.

Eg

22/8/2011 Apple Buy
24/8/2011 Orange Sell
24/8/2011 Apple Sell



So there are many items(like apple,orange), I want to get a way so I can just see if I have that item or not. I thought of using pivot table, but how to create the count?