Decrease price in all records by a specified perctage or amount
We have managed to build an inventory. But periodically we want to decrease the price of of goods. For example we might want to have a sale and so cut the offered price we have listed in the price field of all our records by say 10% or 15% or 20% or maybe decrease it by a fixed amount like £10 or £20, etc.
We'd be very grateful if someone could explain how we might do this. To repeat, we want the price of each item in every single record to be reduced (or maybe even increased) by a percentage or fixed amount. Please bear in mind we are like sub zero literate when it comes to this kind of thing (it took us 6 months just to build the inventory database!).
Many thanks for your kind attention to this matter.