with t as (
    select emp_code as c, emp_last_name as x, emp_first_name as y,
    replace(emp_last_name,' ','')||" "||replace(emp_first_name,' ','') as z
    from emp
    where valid_flg=1
)
select distinct t1.c as CODE, t1.x as SURNAME, t1.y as NAME
from t as t1 inner join t as t2 on t1.c!=t2.c and t1.z=t2.z
order by t1.z, 1