SELECT 
    I.ITEM_CODE AS CODE,
    CASE 
        WHEN IH.ITEM_NAME IS NULL THEN I.ITEM_NAME
        WHEN I.ITEM_NAME <> IH.ITEM_NAME THEN I.ITEM_NAME
        ELSE "NULL"
    END AS NAME
FROM 
    ITEM I
LEFT JOIN 
    ITEM_HISTORY IH ON I.ITEM_CODE = IH.ITEM_CODE
ORDER BY 
    I.ITEM_CODE DESC;