SELECT
     A.EMP_CODE       AS CODE
    ,A.EMP_LAST_NAME  AS SURNAME
    ,A.EMP_FIRST_NAME AS NAME
FROM            (SELECT EMP_CODE, EMP_LAST_NAME, EMP_FIRST_NAME FROM EMP WHERE VALID_FLG = '1') AS A
     INNER JOIN (SELECT EMP_CODE, EMP_LAST_NAME, EMP_FIRST_NAME FROM EMP WHERE VALID_FLG = '1') AS B
     ON REPLACE(A.EMP_LAST_NAME, ' ', '')  = REPLACE(B.EMP_LAST_NAME, ' ', '')
    AND REPLACE(B.EMP_FIRST_NAME, ' ', '') = REPLACE(B.EMP_FIRST_NAME, ' ', '')
    AND A.EMP_CODE                        <> B.EMP_CODE
ORDER BY SURNAME || NAME, CODE
;