select
  e.emp_code as 'CODE',
  e.EMP_LAST_NAME as 'SURNAME',
  e.EMP_FIRST_NAME as 'NAME'
from emp e 
inner join emp e2
  on e.emp_code != e2.emp_code
  and replace(e.EMP_LAST_NAME, ' ', '') = replace(e2.EMP_LAST_NAME, ' ', '')
  and replace(e.EMP_FIRST_NAME, ' ', '') = replace(e2.EMP_FIRST_NAME, ' ', '')
  and e.valid_flg = '1' and e2.valid_flg = '1'
where
  e.valid_flg = '1'
order by
  replace(e.EMP_LAST_NAME, ' ', ''),
  e.emp_code