SELECT
      I.ITEM_CODE CODE
    , CASE 
        WHEN IH.ITEM_CODE IS NULL 
        OR I.ITEM_NAME != IH.ITEM_NAME 
            THEN I.ITEM_NAME 
        ELSE 'NULL' 
        END NAME 
FROM
    ITEM I 
    LEFT JOIN ITEM_HISTORY IH 
        ON I.ITEM_CODE = IH.ITEM_CODE 
ORDER BY
    I.ITEM_CODE DESC;