with
yeah as (
  select
      coalesce(c.ITEM_CODE, o.ITEM_CODE) as CODE
    , coalesce(c.ITEM_NAME, o.ITEM_NAME) as NAME
    , case
         when o.ITEM_CODE is null                              then 'ADDED' 
         when c.ITEM_CODE is null                              then 'DELETED'
         when c.USER_UPDATE_DATETIME != o.USER_UPDATE_DATETIME then 'UPDATED'
         else null
      end as COMP_RSLT
  from
      ITEM c
      full outer join ITEM_HISTORY o using (ITEM_CODE)
)
select
  *
from
  yeah
where
  COMP_RSLT is not null
order by
  CODE desc
;