Select products where the category belongs to any category in the hierarchy

Question

I have a products table that contains a FK for a category, the Categories table is created in a way that each category can have a parent category, example:

Compu         


        

Answer 1

Maybe something like:

select *
from products
where products.category_id IN
  (select c2.category_id 
   from categories c1 inner join categories c2 on c1.category_id = c2.parent_id
   where c1.category = 'Processors'
   group by c2.category_id)

[EDIT] If the category depth is greater than one this would form your innermost query. I suspect that you could design a stored procedure that would drill down in the table until the ids returned by the inner query did not have children -- probably better to have an attribute that marks a category as a terminal node in the hierarchy -- then perform the outer query on those ids.