SELECT
  ITEM_CODE AS CODE,
  ITEM_NAME AS NAME,
  'ADDED' AS COMP_RSLT
FROM
  ITEM
WHERE
  NOT EXISTS(
    SELECT *
    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 *
    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
JOIN
  ITEM_HISTORY
ON
  ITEM.ITEM_CODE = ITEM_HISTORY.ITEM_CODE
  AND ITEM.USER_UPDATE_DATETIME != ITEM_HISTORY.USER_UPDATE_DATETIME

ORDER BY
  CODE DESC