Dynamisk tilføjelse af registreringer med nulværdi for efterfølgende AP'er for at analytisk funktion kan fungere

En ret forenklet tilgang (og ligner det AskTom-linket viser) er at udtrække alle år/måned-par, og alle navn/r_gruppe-par, og derefter krydsforene disse:

with data as (
  select 1 id, 'A' name, 'fruit' r_group, '2007' year, '04' month, 5 sales from dual union all
  select 2 id, 'Z' name, 'fruit' r_group, '2007' year, '04' month, 99 sales from dual union all
  select 3 id, 'A' name, 'fruit' r_group, '2008' year, '05' month, 10 sales from dual union all
  select 4 id, 'B' name, 'vegetable' r_group, '2008' year, '07' month, 20 sales from dual
)
select a.year, a.month, b.name, b.r_group, nvl(d.sales, 0) as sales
from (select distinct year, month from data) a
cross join (select distinct name, r_group from data) b
left join data d on d.year = a.year and d.month = a.month and d.name = b.name and d.r_group = b.r_group
order by year, month, name, r_group;

YEAR MO N R_GROUP        SALES
---- -- - --------- ----------
2007 04 A fruit              5
2007 04 B vegetable          0
2007 04 Z fruit             99
2008 05 A fruit             10
2008 05 B vegetable          0
2008 05 Z fruit              0
2008 07 A fruit              0
2008 07 B vegetable         20
2008 07 Z fruit              0

Men det producerer flere rækker, end du ønskede med dit første niveau for aggregering:

YEAR MO N R_GROUP        SALES    OPENING    CLOSING
---- -- - --------- ---------- ---------- ----------
2007 04 A fruit              5          0          5
2007 04 B vegetable          0          0          0
2007 04 Z fruit             99          0         99
2008 05 A fruit             10          5         15
2008 05 B vegetable          0          0          0
2008 05 Z fruit              0         99         99
2008 07 A fruit              0         15         15
2008 07 B vegetable         20          0         20
2008 07 Z fruit              0         99         99

og når det er aggregeret med dit andet niveau (fra den anden forespørgsel) vil det producere ekstra rækker for f.eks. 2007/04/vegetable:

YEAR MO R_GROUP        SALES    OPENING    CLOSING
---- -- --------- ---------- ---------- ----------
2007 04 fruit            104          0        104
2007 04 vegetable          0          0          0
2008 05 fruit             10        104        114
2008 05 vegetable          0          0          0
2008 07 fruit              0        114        114
2008 07 vegetable         20          0         20

som du delvist kunne filtrere dem fra, før du aggregerede, fordi alle de mellemliggende kolonner ville være nul:

with data as (
  select 1 id, 'A' name, 'fruit' r_group, '2007' year, '04' month, 5 sales from dual union all
  select 2 id, 'Z' name, 'fruit' r_group, '2007' year, '04' month, 99 sales from dual union all
  select 3 id, 'A' name, 'fruit' r_group, '2008' year, '05' month, 10 sales from dual union all
  select 4 id, 'B' name, 'vegetable' r_group, '2008' year, '07' month, 20 sales from dual
)
select year,
       month,
       r_group,
       sum(sales) sales,
       sum(opening) opening,
       sum(closing) closing
from (
  select t.*,
         (sum(sales) over (partition by name, r_group
                           order by year, month
                           rows between unbounded preceding and current row
                          ) -sales ) as opening,
         sum(sales) over (partition by name, r_group
                          order by year, month
                          rows between unbounded preceding and current row
                         ) as closing
  from (
    select a.year, a.month, b.name, b.r_group, nvl(d.sales, 0) as sales
    from (select distinct year, month from data) a
    cross join (select distinct name, r_group from data) b
    left join data d
    on d.year = a.year and d.month = a.month and d.name = b.name and d.r_group = b.r_group
  ) t
)
where sales != 0 or opening != 0 or closing != 0
group by year, month, r_group
order by year, month;

at få:

YEAR MO R_GROUP        SALES    OPENING    CLOSING
---- -- --------- ---------- ---------- ----------
2007 04 fruit            104          0        104
2008 05 fruit             10        104        114
2008 07 fruit              0        114        114
2008 07 vegetable         20          0         20

Du kan yderligere filtrere dette resultat for at fjerne rækker, hvor den samlede salgsværdi stadig er nul, men hvis du gør det, filteret før aggregering er ikke længere nødvendig; men det er stadig lidt rodet. Og det er ikke klart, om din yderste aggregering kan ændres til at gøre det.