select 
	 ifnull(it.ITEM_CODE, ith.ITEM_CODE) as CODE
	,ifnull(it.ITEM_NAME, ith.ITEM_NAME) as NAME
	,case
		when ith.ITEM_CODE is null then 'ADDED'
		when it.ITEM_CODE is null then 'DELETED'
		else 'UPDATED'
	 end as COMP_RSLT
from ITEM it 
	full outer join ITEM_HISTORY ith
	 on it.ITEM_CODE = ith.ITEM_CODE
where
    ith.ITEM_CODE is null
    or it.ITEM_CODE is null
    or it.USER_UPDATE_DATETIME <> ith.USER_UPDATE_DATETIME
order by CODE desc