Help for mysql query!!

I'm trying to solve the problem showed at
http://www.zen-cart.com/forum/showthread.php?t=131048
but I need help with mysql:

I must work with two tables, (TABLE_PRODUCTS_WITH_ATTRIBUTES_STOCK and TABLE_PRODUCTS) and in both I want select records with the condition
where quantity <='" . $stock_reorder_level . "'

The two tables are related by the field products_id and I want retrieve all the records of the first table, and the records of the second table who's products_id IS NOT PRESENT in the first, and finally order with "order by products_id".

Can anybody help me? Thanks - Giovanni

p.s. - when solved this problem I'll post the complete solution.

First
admin > config > stock > Stock Re-order level > set to your value

Next
admin > reports > Product Low Stock

That's the solution I've found:

$products_query_raw = "select * from " .
TABLE_PRODUCTS . " as a " .
" left join " . TABLE_PRODUCTS_WITH_ATTRIBUTES_STOCK .
" as b using (products_id) where
b.quantity <='" . $stock_reorder_level . "' or
a.products_quantity <='" . $stock_reorder_level . "'
order by a.products_id, b.products_id, b.stock_id";

The complete solution is at the link above.

Giovanni