Nu ma stiu in domeniu dar:
http://lichao.net/eblog/how-to-displ...200808164.html

ideea este ca de la asta:
Cod:
SELECT Region, Count(Amount) AS Total
From Sales
Where Amount > 1000
Group By Region_ID
trebuie ajuns la asta:
Cod:
SELECT Region.Region_Name, NVL(SubTotal.Total,0) As SalesTotal
From Region
Left Join
(SELECT Region_ID, Count(Sales.Amount) As Total
From Sales
Where Amount > 1000
Group By Region_ID) SubTotal
On Region.Region_id = SubTotal.Region_ID