select 
ITEM.ITEM_CODE  as CODE,
case
    when ITEM_HISTORY.ITEM_CODE 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