select 
    emp1.emp_code as CODE,
    replace(emp1.emp_last_name,' ','') as SURNAME,
    replace(emp1.emp_first_name,' ','') as NAME
from emp as emp1
inner join emp as emp2
    on  emp1.emp_last_name = emp2.emp_last_name
        and
        emp1.emp_first_name = emp2.emp_first_name
where emp1.VALID_FLG = '1'
order by
    emp1.emp_last_name,
    emp2.emp_first_name,
    emp1.emp_code
    
;