Question

I’m writing this message because I ran out of ideas regarding the implementation of the following thing: given a table with products and another one with product filters, I’d like to retrieve the products according to the selected filters.

Tables look like this:

products:
p_id,
p_name,
p_image

product_filters:
pf_id,
pf_product_id,
pf_filter_id,
pf_filter_value

There is a third table with filter name and id but it’s not so important.

From the HTML form I get an array with filter id and filter value.

I tried to retrieve the id of the products that matched a selected filter, but it only works file for one selected filter. If there are more than one selected filter I won’t get any result.

I’m using PHP and MySQL.

Thanks.

Answer 1

I’m thinking about creating a query like this:

SELECT * FROM products WHERE p_id
IN 
  (
-- this will be repeated in PHP for every filter id and filter value 
    SELECT pf_prod_id FROM product_filters 
    WHERE pf_filter_id = @filterid AND pf_filter_value = @filtervalue
    UNION ALL -- omit this line if it's the last filter id 
-- end repeat
  )

that should do the trick ( although it isn’t the prettiest way to solve it probably )