SELECT
    ITEM.ITEM_CODE AS CODE
    ,CASE WHEN 
            ITEM.ITEM_NAME = ITEM_HISTORY.ITEM_NAME
          THEN 
            NULL
          WHEN
            ITEM.ITEM_NAME <> ITEM_HISTORY.ITEM_NAME
          THEN
            ITEM.ITEM_NAME
          WHEN
            ITEM_HISTORY.ITEM_CODE IS NULL
          THEN
            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;