select EMP_CODE as CODE,
EMP_LAST_NAME as 'SURNAME',
EMP_FIRST_NAME as 'NAME'
from EMP
where
  VALID_FLG = '1' and
replace(EMP_LAST_NAME,' ','') || replace(EMP_FIRST_NAME,' ','') in
(select  replace(EMP_LAST_NAME,' ','') || replace(EMP_FIRST_NAME,' ','') as 'ful'
from EMP
group by ful,VALID_FLG 
having Count(*)>=2
)
order by 
replace(EMP_LAST_NAME,' ','')|| replace(EMP_FIRST_NAME,' ',''),
EMP_CODE