select EMP_CODE as CODE, EMP_LAST_NAME as SURNAME, EMP_FIRST_NAME as NAME
from emp as e1
where replace(EMP_LAST_NAME, ' ', '') in(
    select e2.EMP_LAST_NAME 
    from emp as e2
    where VALID_FLG = '1'
) 
and replace(EMP_FIRST_NAME, ' ', '') in(
    select e2.EMP_FIRST_NAME 
    from emp as e2
    where VALID_FLG = '1'
)
order by replace(SURNAME, ' ', '') , replace(NAME, ' ', ''), EMP_CODE
;