SELECT 
    ITEM.ITEM_CODE AS CODE,
    CASE 
        WHEN ITEM.ITEM_NAME = ITEM_HISTORY.ITEM_NAME THEN "NULL"
        ELSE ITEM.ITEM_NAME
    END AS NAME
FROM
    ITEM
LEFT OUTER JOIN 
    ITEM_HISTORY
ON
    ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE
ORDER BY 
    ITEM.ITEM_CODE DESC