title: Automatically Deduct quantity sold from quantity in the stock and display in datagrid in C#
body: <p>Have been trying this but i havent find the solution. I am trying to implement A POS. So I have 2 database tables one is tblproducts that store the products in the supermarket and has the following fields: productId,ProductName,ProductCategory,Quantity,MinimumQuantity,UnitPrice,Manufacturer. and the second table is tblsales that stores the products tht has been sold and has the followinf fields: ProductId,ProductName,Qty,Unitprice,amount, QuantityRemaining. The information on the tblsales is displayed in the datagridview.</p>
  
  <p>Now i am having a problem whereby I want the system to automatically deduct Qty the customer buys in tblsales from the total Quantity in tblproducts  and display in the datagrid. and also check that the minimum quantity is not reached..
  any Mysql queries someone to help.</p>