select 
    EMP_CODE as CODE
    ,EMP_LAST_NAME as SURNAME
    ,EMP_FIRST_NAME as NAME
from EMP
where EMP_CODE in (
select EMP_CODE
from EMP
where VALID_FLG='1'
group by replace(EMP_LAST_NAME, ' ', ''), replace(EMP_FIRST_NAME, ' ', '')
having count(*)>1
)
order by 2,3,1;