DELETE FROM ITEM
WHERE
(
SELECT 1 FROM ITEM

LEFT OUTER JOIN STOCK
ON ITEM.ITEM_CODE = STOCK.ITEM_CODE
AND STOCK.ITEM_CODE IS NULL

WHERE 0 = 0
AND STOCK_MANAGEMENT_TYPE = 1

OR (LAST_DELIVERY_DATE <= date('sysdate','-6 month')
AND ACTUAL_AMT = 0)

)