Problem in extracting data

Question

Hi All
i am getting problem while extracting data.
XML is .
<po:PurchaseOrder xmlns:po="http://www.oracle.com/PO.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.oracle.com/PO.xsd
http://www.oracle.com/PO.xsd">
<PONum>1005</PONum>
     <Company>Oracle</Company>
<Item>
<Part>9i Doc Set</Part>
<Price>2550</Price>
</Item>
<Item>
<Part>8i Doc Set</Part>
<Price>350</Price>
</Item>
</po:PurchaseOrder>
and i am writing SELECT query as
select p.extract('/(PurchaseOrder/Company)').getStringVal() from po_tab2 p
then i get blank rows.
SQL> select p.extract('/PurchaseOrder/Company').getStringVal() from po_tab2 p;
P.EXTRACT('/PURCHASEORDER/COMPANY').GETSTRINGVAL()
6 rows selected.
but if i use only root element in xpath then it displays result with xml data.
SQL> select p.extract('/PurchaseOrder').getStringVal() from po_tab2 p;
P.EXTRACT('/PURCHASEORDER').GETSTRINGVAL()
<po:PurchaseOrder xmlns:po="http://www.oracle.com/PO.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchem
a-instance" xsi:schemaLocation="http://www.oracle.com/PO.xsd http://www.oracle.com/PO.xsd">
<PONum>1001</PONum>
<Company>Oracle</Company>
<Item>
<Part>9i Doc Set</Part>
<Price>2550</Price>
</Item>
<Item>
<Part>8i Doc Set</Part>
<Price>350</Price>
how can i extract data from child nodes.

Answer 1

seems like problem with the namespace.
pls add the third argument to the extract function i.e the namespace.
select p.extract('/PurchaseOrder/Company', 'target namespace').getStringVal() from po_tab2 p;