select
    ITEM_CODE as CODE
    ,ITEM_NAME as NAME
    ,'ADDED' as COMP_RSLT
from
    ITEM
where  
    not exists(
        select ITEM_CODE
        from ITEM_HISTORY
        where ITEM.ITEM_CODE=ITEM_HISTORY.ITEM_CODE
        )
    
union
select
    ITEM_CODE as CODE
    ,ITEM_NAME as NAME
    ,'DELETED' as COMP_RSLT
from
    ITEM_HISTORY
where
    not exists(
        select ITEM_CODE
        from ITEM
        where ITEM.ITEM_CODE=ITEM_HISTORY.ITEM_CODE
        )

union
select
    ITEM.ITEM_CODE as CODE
    ,ITEM.ITEM_NAME as NAME
    ,'UPDATED' as COMP_RSLT
from
    ITEM
    inner join
    ITEM_HISTORY
    on ITEM.ITEM_CODE=ITEM_HISTORY.ITEM_CODE
where
    ITEM.USER_UPDATE_DATETIME <> ITEM_HISTORY.USER_UPDATE_DATETIME
order by
    CODE desc;