SELECT I.ITEM_CODE AS CODE,
       CASE
         WHEN I.ITEM_NAME <> IH.ITEM_NAME THEN I.ITEM_NAME
         WHEN IH.ITEM_NAME IS NULL 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