select  i.ITEM_CODE as CODE,
case when i.ITEM_NAME != h.ITEM_NAME then i.ITEM_NAME 
     when i.ITEM_NAME == h.ITEM_NAME then null
     when h.ITEM_CODE is null then i.ITEM_NAME 
     else null end as NAME
from ITEM i
left join ITEM_HISTORY h
on h.ITEM_CODE = i.ITEM_CODE
order by i.ITEM_CODE desc