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

Looks like a job for a Common Table Expression.. something along the lines of:

with catCTE (catid, parentid)
as
(
select cat.catid, cat.catparentid from cat where cat.name = 'Processors'
UNION ALL
select cat.catid, cat.catparentid from cat inner join catCTE on cat.catparentid=catcte.catid
)
select distinct * from catCTE

That should select the category whose name is 'Processors' and any of it's descendents, should be able to use that in an IN clause to pull back the products.