select 
ITEM.ITEM_CODE AS CODE

,CASE
    WHEN ITEM_HISTORY.ITEM_NAME IS NULL THEN ITEM.ITEM_NAME
    WHEN ITEM.ITEM_NAME <> ITEM_HISTORY.ITEM_NAME THEN ITEM.ITEM_NAME
    ELSE NULL
END AS NAME
from ITEM
left join ITEM_HISTORY
on ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE
order by ITEM.ITEM_CODE desc