select 
T1.ITEM_CODE CODE
, CASE WHEN T1.ITEM_NAME = T2.ITEM_NAME THEN NULL
       WHEN T1.ITEM_NAME != T2.ITEM_NAME THEN T1.ITEM_NAME
       WHEN T2.ITEM_NAME is null THEN T1.ITEM_NAME
  END NAME
from ITEM T1
LEFT JOIN ITEM_HISTORY T2
ON T1.ITEM_CODE = T2.ITEM_CODE
order by T1.ITEM_CODE DESC;