Little help with database design (ecommerce, mysql)

[eluser]Eric Barnes[/eluser]
I always set my categories up with a parent_id int field. Something like:
id, parent_id, name
1, 0, Parent
2, 1, Child of parent
3, 0, Another parent
4, 2, Child of child 2.
etc...

Then for the products I just have a normal products table that is used in the sorting. Possibly using a secondary product_fields table to hold special extra fields. But probably not needed.