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||EMP_FIRST_NAME, ' ','') in (
        select replace(EMP_LAST_NAME||EMP_FIRST_NAME, ' ','')
        from EMP
        where VALID_FLG='1'
        group by 1
        having count(*)>1
    )
order by replace(EMP_LAST_NAME||EMP_FIRST_NAME, ' ',''), 1;