Purchase Order and PR

select r.segment1 "Req Num",
p.segment1 "PO Num"
from po_headers_all p,
po_distributions_all d,
po_req_distributions_all rd,
po_requisition_lines_all rl,
po_requisition_headers_all r
where p.po_header_id = d.po_header_id
and d.req_distribution_id = rd.distribution_id
and rd.requisition_line_id = rl.requisition_line_id
and rl.requisition_header_id = r.requisition_header_id