SELECT
    i.ITEM_CODE AS CODE,
    CASE
        WHEN ih.ITEM_NAME IS NULL THEN i.ITEM_NAME
        WHEN i.ITEM_NAME <> ih.ITEM_NAME THEN i.ITEM_NAME
        ELSE NULL
    END AS NAME
FROM
    ITEM i
LEFT JOIN
    ITEM_HISTORY ih
ON
    i.ITEM_CODE = ih.ITEM_CODE
ORDER BY
    i.ITEM_CODE DESC;