SELECT 
ITEM.ITEM_CODE  as CODE,
 (CASE WHEN ITEM_HISTORY.ITEM_NAME is  NULL THEN ITEM.ITEM_NAME
       WHEN ITEM.ITEM_NAME <>  ITEM_HISTORY.ITEM_NAME THEN ITEM.ITEM_NAME
       WHEN ITEM.ITEM_NAME = ITEM_HISTORY.ITEM_NAME THEN NULL
  END)  AS  NAME  
FROM ITEM 
LEFT JOIN ITEM_HISTORY
on ITEM.ITEM_CODE =  ITEM_HISTORY.ITEM_CODE
ORDER BY CODE DESC