Réponse trouvée :
select t.*
from xmltable(xmlnamespaces(default 'http://www.opengis.net/wfs'
,'http://www.opengis.net/gml' as "gml"
,'http://www.opengis.net/wfs' as "wfs"
,'http://www.opengis.net/ows' as "ows"
,'http://www.w3.org/1999/xlink' as "xlink"
,'http://www.w3.org/2001/XMLSchema-instance' as "xsi"
,'http://www.opengis.net/ogc' as "ogc")
,'for $d in //ows:Operation/ows:Parameter/ows:Value
where $d/../../@name = "GetFeature"
and $d/../@name="outputFormat"
return $d' passing p_xml columns value varchar2(100) path '/') as t;
en utilisant l'expression .. xpath pour accéder aux nœuds parents.
