php5 - Displaying hierarchical data as tree

I have the following query to my categories table:

SELECT l1.id as lev1_id,l2.id as lev2_id,l3.id as lev3_id,l1.category AS lev1, l2.category as lev2, l3.category as lev3
FROM categories AS l1
LEFT JOIN categories AS l2 ON l2.parentCat = l1.id
LEFT JOIN categories AS l3 ON l3.parentCat = l2.id
WHERE l1.parentCat = NULL


Which outputs something like:
-------------------------------------------------------
lev1_id | lev2_id | lev3_id |lev1 | lev2 | lev3 |
------------------------------------------------------
1 | 4 | 7 |makeup | lipstick | wet look
1 | 4 | 8 |makeup | lipstick |matt
1 | 5 | 9 |makeup | mascara| black
2 | 11 | NULL|skincare|creame | NULL
3 | 12 | 13 |haircare |hairspray| Xtra Hold


I want to be able to display this data as a tree with 3 levels. I know a foreach os a good place to start but dont know what after that.

Any help would be much appreciated.

I'm not quite sure what you mean, but you can display the variables anyway you wish.

I imagine you have a nested array in your main array of data... So each row = its own array...

If thats the case then this would work (to display the variables).