--
-- ec_order_cost/1
--
create or replace function ec_order_cost(
  integer
) returns numeric as $$

DECLARE
	v_order_id	alias for $1;
        v_price         numeric;
        v_shipping      numeric;
        v_tax           numeric;
        v_certificate   numeric;
BEGIN
        v_price := ec_total_price(v_order_id);
        v_shipping := ec_total_shipping(v_order_id);
        v_tax := ec_total_tax(v_order_id);
        v_certificate := ec_order_gift_cert_amount(v_order_id);

        return v_price + v_shipping + v_tax - v_certificate;
END;$$ language plpgsql;