How to do mass updates on entity beans?

[Bob Walker Jr]

Lets say I have a product database and each product has a catagory and discuount%. What I need to do is change the discount% of all the products of a category. I am thinking of having a home business method in the home interface: public void changeDiscount(String category, double newdiscount);
This method would then fire a query like: update product set discount=? where category=?
My question is: Is this a valid approach? Can I even specify such a query in the deployment descriptor? If I do that, what would happen to the discount values of the bean that are currently in use?
If this is not a valid approach, how should I update the discount value for each product?

[Ramon Gill]

Bob, shouldn't the percentage be held in the category? this would avoid mass updates (only 1 row updated in category instead).
If you wanted to do mass updates, I would have thought the best way would be to avoid entity beans, and use a DAO called by a session bean.
Ray Gill
SCJP, SCWCD