Stock update (Help me)

[meenctg]

I have two tables in my database. Here ProductId are in relationship. I wanna when user entry stock by the "tbl_stockIn" it will update product stcok in tbl_Product. How can i'll do? please help me anybody. tbl_Product ( ProductId ProductName Stock ) tbl_StockIn (Sl Date ProductId Quantity)

 

[Galaxiom]

It is usually best not to maintain a Quantity field in an inventory table.

Calculate the stock by summing the inward and outward transactions whenever the inventory quantity is required for display.