select 
EMP_CODE as CODE
, emp_last_name as SURNAME
, emp_first_name as NAME
from emp where valid_flg = '1' and 
exists (
select 1 from emp as emp2
where replace(emp.emp_last_name, ' ', '') = replace(emp2.emp_last_name, ' ', '') and replace(emp.emp_first_name, ' ', '') = replace(emp2.emp_first_name, ' ', '') and emp.emp_code != emp2.emp_code
)
order by replace(SURNAME, ' ', '') asc, code asc