select
  main.ITEM_CODE as CODE
 ,main.ITEM_NAME as NAME
 ,'ADDED' as COMP_RSLT
from
    ITEM as main
left join
    ITEM_HISTORY as sub using(ITEM_CODE)
where
     sub.USER_UPDATE_DATETIME is null
union ALL
select
  main.ITEM_CODE as CODE
 ,main.ITEM_NAME as NAME
 ,'UPDATED' as COMP_RSLT
from
    ITEM as main
left join
    ITEM_HISTORY as sub using(ITEM_CODE)
where
    main.USER_UPDATE_DATETIME > sub.USER_UPDATE_DATETIME
union all
select
  main.ITEM_CODE as CODE
 ,main.ITEM_NAME as NAME
 ,'DELETED' as COMP_RSLT
from
    ITEM_HISTORY as main
left join
    ITEM as sub using(ITEM_CODE)
where
     sub.USER_UPDATE_DATETIME is null
order by
     CODE desc