postgresql7.1
select coalesce(shipping_charged,0) - coalesce(shipping_refunded,0)
from ec_orders
where order_id=:order_id
select i.item_id, p.product_name, i.price_charged, coalesce(i.shipping_charged,0) as shipping_charged
from ec_items i, ec_products p
where i.product_id=p.product_id
and i.item_id in ([join $item_id_list ", "])
and i.item_state in ('shipped','arrived')
select i.item_id, p.product_name, i.price_charged, coalesce(i.shipping_charged,0) as shipping_charged
from ec_items i, ec_products p
where i.product_id=p.product_id
and i.order_id=:order_id
and i.item_state in ('shipped','arrived')