SELECT
    E1.EMP_CODE CODE,
    E1.EMP_LAST_NAME SURNAME,
    E1.EMP_FIRST_NAME NAME
FROM
    EMP AS E1
WHERE
    E1.VALID_FLG = '1'
    AND
    REPLACE(E1.EMP_LAST_NAME || E1.EMP_FIRST_NAME ,' ','') IN (
        SELECT REPLACE(E2.EMP_LAST_NAME || E2.EMP_FIRST_NAME ,' ','')
        FROM EMP E2
        WHERE E2.EMP_CODE <> E1.EMP_CODE
        AND E2.VALID_FLG = '1'
    )
ORDER BY
    REPLACE(E1.EMP_LAST_NAME || E1.EMP_FIRST_NAME ,' ','') ASC,
    E1.EMP_CODE ASC
;