WITH
    TMP AS (
        SELECT
            EMP_CODE AS CODE,
            EMP_LAST_NAME AS SURNAME,
            EMP_FIRST_NAME AS NAME,
            REPLACE (EMP_LAST_NAME || EMP_FIRST_NAME, ' ', '') AS EMP_NAME
        FROM
            EMP
        WHERE
            VALID_FLG = '1'
    )
SELECT
    t1.CODE AS CODE,
    t1.SURNAME AS SURNAME,
    t1.NAME AS NAME
FROM
    TMP AS t1
    INNER JOIN TMP AS t2 ON t1.CODE != t2.CODE
    AND t1.EMP_NAME = t2.EMP_NAME
ORDER BY
    t1.EMP_NAME ASC,
    t1.CODE ASC;