I would have a single table, called user_pref, which would have the columns user_id, product_type_id, both of which would form the primary key for the table. If the user selects pets as a preferred option, add their user id and the pets category's id to the table. If the user then also selects the gardening category, add that to the table to.

When you display the items, check the table for preferences and if there is at least one row for their user id only display items in the categories listed, otherwise display items from all categories.

Hope this helps
darkagn

I would suggest also making a dedicated table for the user preferences. However I would suggest making a column for each preference. Eg. user_id, gardening, pet, food.

As for the pets, gardening and food tables, it is a good idea to make as many tables in your database as possable, this means you wont overstress a single table.

So in a sense, when the user sellects pet and food you will check the table for the users ID if there is already and ID then edit that row else make a new one. The idea is add a 1 into the column the chose, in the instance it is pet and food,

This will make the row look like this:

ID --- Pet --- Gardening --- Food
----------------------------------------
984 1 0 1
======================

So if they have a 1 in any of the topics then you will retreive the rows from the specified tables.

This is the most ligical way to my knowledge.

work as charm!