recusrion

Hi,

I'm doing a portal and have a recursion problem.
I just need advice on whether or not I'm wasting my time in thinking I can
do what I need with SQL.
We're basically building a yahoo-like portal. My categories table is as
follows this email.
Each category has a primary key and an owner (the owner is the primary key
of the category owning that category). I want to extract a site map in one
query: ie: extract the cetagory and its subcategories if any and any of the
subcategories' subcategories if any etc ....
Right now, in failure to do so with SQL, I'm selecting the whole thing in a
hash array in perl and reorganising it (which is fine, it worksm but if it
can be "cleaner", that's better !), but I was wondering if I should
continue looking for the SQL answer ... I've seen similar things done, but
somehow it's slightly different to this case and I can't seem to see it !
I've written a few functions that lead me nowhere, performed self joins etc
... but I think I'm looking at it from the wrong angle ... any suggestions ?
Thanks.

id|owner|name
--+-----+-------------------------
2| 0|Business
9| 7|How to learn
12| 9|Good schools
13| 12|Good schools in Melbourne
14| 13|Good schools in Carlton
16| 6|Victorian Private Banks
17| 1|Barbeques
18| 17|Victorian barbeques
3| 1|Sports
4| 2|Banking
5| 3|Tennis
6| 4|Victorian Banks
7| 5|Lessons
8| 2|Finance
1| 0|Outdoors
0| 0|Home
19| 5|Tennis Clubs
20| 19|Melbourne CLubs
21| 5|Tournaments
22| 13|Free tuition