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