select tep.prd_id, tp.prd_name, sum(tep.quantity) as total from tbl_event_prd tep left join tbl_prd tp on tep.prd_id=tp.prd_id group by prd_id, prd_name order by total desc
select A.quantity,C.prd_name from tbl_event_prd A left join tbl_event B on A.sto_id=B.sto_id left join tbl_prd C on A.prd_id=C.prd_id order A.quantity desc
from tbl_event_prd tep left join tbl_prd tp
on tep.prd_id=tp.prd_id
group by prd_id, prd_name
order by total desc