Query for grade change on particular date

Hello,

I'm looking for Query which displays for a grade change on a particular date. The output includes if employees holding multiple assignments.

select papf.employee_number,papf.full_name,paaf_old.assignment_number oldassignment,paaf_new.assignment_number newassignment,

pg_old.name old_grade, pg_new.name new_grade,paaf_new.effective_start_date change_date

from apps.per_all_people_f papf,

apps.per_all_assignments_f paaf_old,

apps.per_grades pg_old,

apps.per_all_assignments_f paaf_new,

apps.per_grades pg_new

where 1=1

and papf.person_id = paaf_old.person_id

and papf.person_id = paaf_new.person_id