How to minus a number in the same table

[hungnguyenjn]

I am write a asp.net application, I want to make a report by connect to access database to take out the result. but I don't know how to do. In addition, My English is just a little so I can not describe my idea. please, forgive me, if you don't understand what I describe. :(
My access data have a table such as below:
product Quantity status date/time
P0001 1 In
P0002 3 out
P0003 1 in
P0004 2 in
P0005 4 out
P0006 3 in
P0006 3 out
P0003 3 in
P0001 1 In

I want to calculate the quantity of these products after in and out but I don't know how to find out. I want the result like below:
product quantity
P0001 2
P0002 -3
P0003 4
P0004 2
P0005 -4
P0006 0
Please, help me!

[Delerna]

I am guessing you are asking for the query you need to write in access.

So something like this
[code=sql]
SELECT Product,sum(iif (status="IN",Qu antity,Quantity *-1)) as Qty
FROM YourTable
GROUP BY Product
[/code]