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, ' ', '') as EMP_NAME 
        from
            emp 
        WHERE
            VALID_FLG = '1' 
        group by
            EMP_NAME 
        having
            count(EMP_NAME) >= 2
    ) 
order by
    replace (EMP_LAST_NAME || EMP_FIRST_NAME, ' ', '') asc
    , emp_code asc