How to query for XML-attribute with XPATH

Question

Hi,
Isn't there somebody, who can tell me how to query an Attribut of an XML-element correctly ?
All my trials lead to empty rows. What's worng in my XPATH-expresion ?
XML-file looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<xmlexport>
<itsystem guid="e51b91d1-ab0f-11db-2cd7-001641105333">
<field fieldidentifier="currentVersion" />
<field fieldidentifier="marketdatacosts">0</field>
I can query fine the elements and sub-elements, but not attribute 'guid' of /xmlexport/itsystem. Here some trials, all lead
SELECT t.* FROM CORIA."xmlexport156_TAB", xmltable ('/xmlexport/itsystem ' passing object_value COLUMNS
GUID     VARCHAR2(1000) path '[@guid=*]') t
various versions for Xpath:
path '[@guid="*"]'
path '/[@guid=*]'
path '[@guid=*]'
xmltable ('/xmlexport' ...
path '/itsystem/[@guid=*]'
... combinations of part 1 and 2
thanks for any hint, LaoDe

Answer 1

You can either get them directly, or fetch the attribute in your xquery and put them in returning xml fragment, then get them like normal element.
Method #1:
path '@guid'
Method #2:
xmltable(
let $is := /xmlexport/itsystem
return <r><guid>{$is/@guid}</guid></r>
passing object_value
columns guid varchar2(1000) path '/r/guid')