WITH data AS (
    SELECT
        EMP_CODE,
        EMP_LAST_NAME,
        REPLACE(EMP_LAST_NAME, ' ', '') AS R_LAST_NAME,
        EMP_FIRST_NAME,
        REPLACE(EMP_LAST_NAME, ' ', '') AS R_FIRST_NAME
    FROM EMP
    WHERE VALID_FLG = '1'
)
SELECT
    a.EMP_CODE AS CODE,
    a.EMP_LAST_NAME AS SURNAME,
    a.EMP_FIRST_NAME AS NAME
FROM
    data a
    CROSS JOIN data b
WHERE
    a.EMP_CODE <> b.EMP_CODE
AND
    a.R_LAST_NAME = b.R_LAST_NAME
AND
    a.R_FIRST_NAME = b.R_FIRST_NAME
ORDER BY
    a.R_LAST_NAME || a.R_FIRST_NAME ASC,
    a.EMP_CODE ASC