Query deducting values row by row

Question

hi !
I have a table of products with fields (product, qtty, fixed value) and i need to make a query to show a list of values deducting a qtty of a fixed value but adding the qtty by product. For example:
PRODUCT......QTTY......FIXED VALUE....RESULT
AAAAAAA......1000.............5000..................4000
AAAAAAA........800.............5000..................3200
AAAAAAA........900.............5000..................2300
BBBBBBB........200...............700....................500
BBBBBBB........100...............700....................400
i tried use lead and lag but unitl now i can´t to solve my problem.
thank´s
Fernando.

Answer 1

SELECT
   product,
   qty,
   fixed,
   fixed - SUM(qty) OVER (PARTITION BY product ORDER BY rn) left
FROM
    SELECT
       product,
       qty,
       fixed,
       fixed - qty left,
       row_number() OVER (PARTITION BY product ORDER BY qty) rn
    FROM
        SELECT 'A' product, 1 qty, 10 fixed FROM dual
        UNION ALL
        SELECT 'A' product, 1 qty, 10 fixed FROM dual
        UNION ALL
        SELECT 'A' product, 1 qty, 10 fixed FROM dual
        UNION ALL
        SELECT 'B' product, 3 qty, 20 fixed FROM dual
P        QTY      FIXED       LEFT
A          1         10          9
A          1         10          8
A          1         10          7
B          3         20         17Message was edited by:
le848dave
used row_number to fix multiple of same quantity for one product problem