select a.ITEM_CODE as CODE, 
(CASE
    WHEN a.ITEM_NAME <> b.ITEM_NAME THEN a.ITEM_NAME
    WHEN a.ITEM_NAME = b.ITEM_NAME THEN NULL
    ELSE a.ITEM_NAME
END)as NAME
from ITEM a left join ITEM_HISTORY b on a.ITEM_CODE = b.ITEM_CODE
order by a.ITEM_CODE desc