SELECT IH.ITEM_CODE AS CODE
      ,IH.ITEM_NAME AS NAME
      ,'DELETED' AS COMP_RSLT
  FROM ITEM_HISTORY IH
WHERE NOT EXISTS(SELECT 1
                   FROM ITEM I
                  WHERE IH.ITEM_CODE = I.ITEM_CODE)
UNION ALL
SELECT I.ITEM_CODE AS CODE
      ,I.ITEM_NAME AS NAME
      ,'ADDED' AS COMP_RSLT
  FROM ITEM I
WHERE NOT EXISTS(SELECT 1
                   FROM ITEM_HISTORY IH
                  WHERE IH.ITEM_CODE = I.ITEM_CODE)
UNION ALL
SELECT IH.ITEM_CODE AS CODE
      ,IH.ITEM_NAME AS NAME
      ,'UPDATED'AS COMP_RSLT
  FROM ITEM_HISTORY IH
 INNER JOIN ITEM I
    ON IH.ITEM_CODE = I.ITEM_CODE
WHERE IH.USER_UPDATE_DATETIME <> I.USER_UPDATE_DATETIME
 ORDER BY CODE DESC