SELECT 
EMP_CODE CODE,
EMP_LAST_NAME SURNAME,
EMP_FIRST_NAME NAME
FROM EMP
WHERE VALID_FLG = '1'
AND REPLACE(EMP_LAST_NAME || EMP_FIRST_NAME ,' ','') IN(
SELECT REPLACE(EMP_LAST_NAME || EMP_FIRST_NAME ,' ','') AS NAME
FROM EMP
WHERE VALID_FLG = '1'
GROUP BY NAME
HAVING COUNT(*)>=2
)
ORDER BY REPLACE(EMP_LAST_NAME || EMP_FIRST_NAME ,' ',''),
EMP_CODE