select
    case 
        when ITEM.ITEM_CODE is null then ITEM_HISTORY.ITEM_CODE
        else ITEM.ITEM_CODE
    end as CODE
    ,case 
        when ITEM.ITEM_NAME is null then ITEM_HISTORY.ITEM_NAME
        else ITEM.ITEM_NAME
    end as NAME
    ,case
        when ITEM_HISTORY.USER_UPDATE_DATETIME is null then "ADDED"
        when ITEM.USER_UPDATE_DATETIME != ITEM_HISTORY.USER_UPDATE_DATETIME then "UPDATED"
        else "DELETED"
    end AS COMP_RSLT
from 
    ITEM_HISTORY
full outer join ITEM
on ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE
order by CODE desc