select e.EMP_CODE as CODE, e.EMP_LAST_NAME as SURNAME, e.EMP_FIRST_NAME as NAME
from 
(
select p.EMP_CODE, REPLACE(p.EMP_LAST_NAME||p.EMP_FIRST_NAME,' ','') as name
from EMP as p
where p.VALID_FLG = '1'
) as e2
INNER JOIN EMP as e
ON REPLACE(e.EMP_LAST_NAME||e.EMP_FIRST_NAME,' ','') = e2.name AND e.EMP_CODE <> e2.EMP_CODE AND e.VALID_FLG = '1'
order by e2.name, e.EMP_CODE