I'd recommend a column of type SET.
Read about it here: http://www.mysql.com/doc/en/SET.html
Basically, if your list of product types is static, this may be a good bet. The SET
type can store any combination of 64 members,
stored as bits.
To list all items int a product type, you might use some
If you have, and always will have, no more that 64 product types, you can
store the product type in a SET field. This is effectively a hybrid between
your list and boolean solutions. MySQL stores this as a bitmap with one bit
per product type and
provides the appropriate query methods. You can the
What you're talking about is a many-many relationship, as one product can
belong to many categories, and one category can encompass many products.
The best way to implement this is to have a [category] table, a [product]
table, and a [categoryproduct] table. The latter table implements the
many-ma