InfoPath Dev

Hello Thank you for your reply. Do you mean I have to call the id and quantity and update the new value manually? Is there anyway I just put additional quantity and ID so system will calculate the total and update the quantity for the inventory? Please be advised. Thank you.  

Hello. I am trying to make purchase order with MSSQL 2005. Once I insert inventoryID and quantity, I want the quantity value to be added on current quantity value saved in item table. Is it possible to do it in infopath?  Please be advised. Thank you.