SELECT
  EMP_CODE AS CODE,
  EMP_LAST_NAME AS SURNAME,
  EMP_FIRST_NAME AS NAME
FROM EMP
INNER JOIN 
(
SELECT REPLACE(EMP_LAST_NAME,' ','') AS LAST, REPLACE(EMP_FIRST_NAME,' ','') AS FIRST, COUNT(*)
FROM EMP
WHERE VALID_FLG = '1'
GROUP BY REPLACE(EMP_LAST_NAME,' ',''), REPLACE(EMP_FIRST_NAME,' ','')
HAVING COUNT(*) > 1
) TBL2
ON REPLACE(EMP_LAST_NAME,' ','') = TBL2.LAST AND REPLACE(EMP_FIRST_NAME,' ','') = TBL2.FIRST
WHERE VALID_FLG = '1'