select
    emp.EMP_CODE as CODE,
    emp.EMP_LAST_NAME as SURNAME,
    emp.EMP_FIRST_NAME as NAME 
from 
    (
    select 
        count(replace(emp2.emp_last_name, ' ','') || replace(emp2.emp_first_name, ' ','')) as cnt,
        replace(emp2.emp_last_name, ' ','') || replace(emp2.emp_first_name, ' ','') as full_name,
        emp2.emp_code,
        emp2.emp_last_name,
        emp2.emp_first_name from emp as emp2
    where
        emp2.valid_flg = 1
    group by
        full_name
    ) as emp_cnt
inner join 
    emp on emp_cnt.cnt > 1
        and replace(emp.emp_last_name, ' ','') || replace(emp.emp_first_name, ' ','') = emp_cnt.full_name
where 
    emp.valid_flg = 1
order by 
    replace(emp.emp_last_name, ' ','') || ' ' || replace(emp.emp_first_name, ' ',''),
    emp.emp_code
;