select
sp2.sale_id,
sum(sp2.payment_amount) as sumpaid,
sik2.quantity_purchased,
sik2.item_kit_unit_price,
sik2.discount_percent,
min(sp2.payment_date) as payment_date
from
sales_payments sp2,
sales_item_kits sik2,
sales_item_kits_taxes sit2
where
sik2.sale_id=sp2.sale_id
and sit2.sale_id=sp2.sale_id
group by
sp2.sale_id
Please help simplifying this query with (OUTER/LEFT?) JOIN which all of table doesn't have same rows amount.. thanks in advance