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