select
     MST.ITEM_CODE as CODE
    ,case
        when MST.ITEM_NAME = HIST.ITEM_NAME 
            then null
        else
            MST.ITEM_NAME
    end             as  NAME  
from ITEM as MST
left join ITEM_HISTORY as HIST
on HIST.ITEM_CODE = MST.ITEM_CODE
order by CODE desc;