E-Commerce DB Design

I am hoping to get some general advise on database design for an e-commerce website. Looking at the number of online shops on the web got me thinking as to how they implement their databases. Sites like Amazon.co.uk sell loads of products in different categories e.g. CD's, Books, Electronics. Products in different categories have different data describing the product e.g. Books have an ISBN number but CD's and Electronics do not. Would that database actually have different tables for each category to avoid redundancy? There would be no point in storing, for example, ISBN for a CD because the field would be blank.

If anyone has got a sample Entity Relationship diagram showing the database design for a complex array of product categories, could you possibly send it to me. Any other wisdom would also be much appreciated!

Thanks,

Andy

There are a few different ways this can be tackled. I have done something similar and use one central products table to store all of the data common between products. There was a seperate table for all the non-common information per category. Instead of hard coding the table names for the categories they were listed in the table next to the category. When I wanted to access the extra details just looked up the table name and then ran the sql query.

The Library of Congress has already addressed this issue, and I believe Amazon et al base their model on the LOC dataset concept with is DAP based. You can use LDAP to set up yours if you are brave

The LOC has an entire project devoted to this service.

Thanks for your help guys, i am going to delve a bit deeper now...

Andy