Relation Between Requisition and PO

SELECT prha.segment1 "REQ NUM", pha.segment1 "PO NUM"

  FROM po_headers_all pha,

       po_distributions_all pda,

       po_req_distributions_all prda,

       po_requisition_lines_all prla,

       po_requisition_headers_all prha

 WHERE     pha.po_header_id = pda.po_header_id

       AND pda.req_distribution_id = prda.distribution_id

       AND prda.requisition_line_id = prla.requisition_line_id

       AND prla.requisition_header_id = prha.requisition_header_id