Best way to select from 2 tables, based on sum from detail table

Question

I have a "customer order line detail" table from which I want to report
Order Number
Customer Number
Part Number
Line Value { which is Unit Qty * (Unit price - discount%) }
But only for orders which are above £1500.
And lines which are not "Cancelled"
I have access to an API which returns the total order value for the order.
I am currently using this in my criteria, eg:
select order_no, customer_no, part_no, round(unit_qty *(unit_price - unit_price *(discount/100)),2) Line_value
from customer_detail
where
status != 'Cancelled'
and
Customer_Order_API.Get_Total_Sale_Price__(order_no)>=1500
The API contains the following:
SELECT SUM(ROUND((qty * price_conv_factor * unit_price), rounding_) -
ROUND((qty * price_conv_factor * unit_price) -
((qty * price_conv_factor * unit_price) * ((1 - discount / 100) * (1 - order_discount / 100))), 2))
FROM customer_detail
WHERE order_no = order_no_
AND state != 'Cancelled'
AND line_item_no <= 0
(that uses a price conversion factor that I don't use, since it's always 1)
My query runs so slowly, because it is getting the order value for every line of the order, is it possible to improve?
Thanks

Answer 1

Thanks for the suggestion, it was close to what I needed.
I ended up with this:
select order_no,  name, ref_id, c_salesman_sub_division, line_value, catalog_desc
from
(SELECT coj.customer_no, coj.order_no, ifsapp.customer_info_api.GET_NAME(customer_no) name, coj.ref_id,
       coj.c_salesman_sub_division, ROUND((coj.buy_qty_due * coj.
       price_conv_factor) * coj.sale_unit_price, 2) - ROUND((coj.buy_qty_due *
       coj.price_conv_factor) * coj.sale_unit_price - ((coj.buy_qty_due * coj.
       price_conv_factor) * coj.sale_unit_price) * ((1 - coj.discount / 100) *
       (1 - coj.order_discount / 100)), 2) line_value, coj.catalog_desc,
SUM( ROUND((coj.buy_qty_due * coj.
       price_conv_factor) * coj.sale_unit_price, 2) - ROUND((coj.buy_qty_due *
       coj.price_conv_factor) * coj.sale_unit_price - ((coj.buy_qty_due * coj.
       price_conv_factor) * coj.sale_unit_price) * ((1 - coj.discount / 100) *
       (1 - coj.order_discount / 100)), 2)) OVER (PARTITION BY Coj.ORDER_NO) AS SUM_ORDER
    FROM ifsapp.customer_order_join coj
    WHERE coj.order_no = coj.order_no
      AND TRUNC(coj.date_entered) = NVL(TO_DATE('25/01/2007', 'DD/MM/YYYY'),
          TRUNC(SYSDATE))
      AND coj.authorize_code = 'UKMEDM'
      AND coj.line_item_no >= 0
      AND coj.ref_id <> 'SAMP'
      AND coj.state <> 'Cancelled'
where sum_order >=1500
    ORDER BY ref_id, c_salesman_sub_division, customer_no, order_no
/[pre]
But I have realised the problem with this.  Not sure if I made it clear, to myself even, but I need to include
order lines added on a particular day (that are not cancelled)
for orders which total >= £1500.
If one line of an order is added for £900 but the rest of the order is £2000 then that line should be shown.
My SQL only shows lines added for the day >= 1500.