PO与PR之间的关系SQL

select ph.segment1 po_num,pl.line_num po_line_num,prh.segment1 pr_num,prl.line_num pr_line_num
from po_lines_all pl,
     po_headers_all ph,
     po_line_locations_all pll,
     po_requisition_headers_all prh,
     po_requisition_lines_all prl
where pl.po_header_id=ph.po_header_id
and pl.po_line_id=pll.po_line_id
and prl.line_location_id=pll.line_location_id
and prl.requisition_header_id=prh.requisition_header_id