To find organization employee designation

/*Employee Designation*/
select papf.employee_number,
       papf.full_name,
       paaf.effective_start_date start_date,
       paaf.effective_start_date end_date,
       paaf.ass_attribute10
from
apps.per_all_people_f papf,
apps.per_all_assignments_f paaf,
apps.per_grades pg
where 1=1
and papf.person_id = paaf.person_id
and paaf.grade_id = pg.grade_id
and papf.employee_number = nvl(:empno, papf.employee_number)
--and papf.full_name like '%%'
order by
        start_date desc