>I have a transaction table A (brand, prod_id, prod_age, in, out). My user needs a delivery pick-up list report. The pick-up requirement is usually based on brand. For example, brand A, I need 300, brand B, I need 200, etc., '300' can be 20 from prod_1, 50 from prod_2, etc. The oldest product should be pick-up first for each brand. The requirement is stored in another table B (brand, req_qty)

let me try :
select a.brand, a.prod_id, b.req_qty, a.in, a.out ;
from a table_A, b table_B ;
where (a.brand = b.brand) order by 1

hope it helps. keep experimenting with sql, it's fun. just remember
to read their article on sql on the knowledge base because there's
something about not getting the correct records but i always use
_tally anyway.