SELECT DISTINCT e.EMP_CODE AS "CODE",
e.EMP_LAST_NAME AS "SURNAME",
e.EMP_FIRST_NAME AS "NAME"
FROM EMP e LEFT OUTER JOIN EMP m 
ON e.EMP_LAST_NAME = REPLACE(m.EMP_LAST_NAME,' ','')
AND e.EMP_FIRST_NAME = REPLACE(m.EMP_FIRST_NAME,' ','')
WHERE e.VALID_FLG = '1'
ORDER BY REPLACE(e.EMP_LAST_NAME,' ','')||REPLACE(e.EMP_FIRST_NAME,' ','') ASC,
e.EMP_CODE ASC;