Можете да опитате това:
SELECT T0.ItemCode,
SUM(CASE WHEN YEAR(T0.DocDate) = 2011 THEN QUANTITY ELSE 0 END) AS '2011',
SUM(CASE WHEN YEAR(T0.DocDate) = 2012 THEN QUANTITY ELSE 0 END) AS '2012'
FROM MyTable T0
GROUP BY
T0.ItemCode