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