Database design for hibernate

[NubKnacker]

Hi,
I'm a hibernate beginner and I have a very small seam application i'm building. Obviously hibernate is to be used but i'm a little confused as to what the database design should be. The application is basic:
1. Two types of materials exist, raw material and processed materials.
2. A processed material is to be constructed from two or more raw materials.
3. The price of the raw materials is to be entered by the user and saved in the database.

The basic design I have been able to come up with is placed as an image here. The problem with the design is that there is no way that I can load the quantity of the material as well without creating a seperate class from the base raw material class. The quantity can vary from 1 to 100 so can't hardcode it either. Any ideas? suggestions?

Thanks.

[Hack]

Welcome to DevX

What is the issue with creating another class?

What database are you going to be using?

What have you decided on for a primary key?

[NewUniverse]

You can use raw sql to insert the values in the relevant DB table with prices.

Still it is much better if you use another class as this way you will have the hibernate version control and you can freely use all the feature that hibernate provides for you.

With Seam and JBoss you do not have to use Hibernate. They integrate it and they provide it for you as default in the same way as Oracle container provide toplink for you. So feel free to use whatever you like. I think that Hibernate is a great choice and you can benefit a lot.