with 
TMP as (
select
    coalesce(P.ITEM_CODE, S.ITEM_CODE) as ITEM_CODE
    ,coalesce(P.ITEM_NAME, S.ITEM_NAME) as ITEM_NAME
    ,case
        when S.ITEM_CODE is null then 'ADDED'
        when P.ITEM_CODE is null then 'DELETED'
        when P.USER_UPDATE_DATETIME <> S.USER_UPDATE_DATETIME
            then 'UPDATED'
        else null end as COMP_RSLT
from
    ITEM P
    full outer join
        ITEM_HISTORY S 
        on 
            P.ITEM_CODE=S.ITEM_CODE
)


select
    ITEM_CODE as CODE
    ,ITEM_NAME as NAME
    ,COMP_RSLT
from 
    TMP
where
    COMP_RSLT is not null
order by 1 desc