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(*) >= 2) 
order by
replace (emp_last_name || emp_first_name, ' ', '') asc
, emp_code asc;