si votre SGBDR prend en charge la fonction de fenêtre,
pour SQL Server 2012
SELECT Qty,
SUM(Qty) OVER (ORDER BY Qty) AS CumulativeTOTAL
FROM tableName
pour SQL Server 2008
SELECT a.Qty, (SELECT SUM(b.Qty)
FROM TableName b
WHERE b.Qty <= a.Qty)
FROM TableName a
ORDER BY a.Qty;