I have two tables Quantity and Purchases. When I purchase a product, first I have to check either it's old product or new. If it's Old means I have purchased before and its details already saved in the Database in Quantity Table so it will update the AvailableQuantity field only in the Quantity Table. Else if it's a new Product it must add new row in the Quantity Table with all details of the product.
I hope it's clear for all
I need your comment. How to do it with Trigger (
IF Exist Update else Insert ) or give me another solution.