Problems fecthing with xmltable using xmlnamespaces

Question

Hi, I've the following XML save in a table in a XMLTYE field
<ORU_R01 xmlns="urn:hl7-org:v2xml" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<MSH>
<MSH.1>|</MSH.1>
<MSH.7>
<TS.1>200804090000</TS.1>
</MSH.7>
</MSH>
</ORU_RO1>
When I've tried to retrive it using the SQL statment below, it doesn't fetch any record
select m.*
from HA.Hl7_Messages h,
xmlTable
( XmlNamespaces('urn:hl7-org:v2xml' AS xmlns),
'/ORU_R01'
passing h.msg
Columns
CA VARCHAR2(10) Path 'MSH/MSH.1',
CB VARCHAR2(30) Path 'MSH/MSH.7/TS.1',
) m
I used xmlTable WITHOUT namespaces and works fine, but here I think that is a namespace problem. I've tried adding the namespace (eg,/xmlns:ORU_RO1) in different ways but nothings happens.
Any idea?

Answer 1

<ORU_R01 xmlns="urn:hl7-org:v2xml"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
Your document is namespaced indeed, and you chose to define your namespace as the "default" namespace in the document, but don't confused xmlns to be your namespace prefix. It's not.
select m.*
from HA.Hl7_Messages h,
xmlTable
( XmlNamespaces('urn:hl7-org:v2xml' AS xmlns),
'/ORU_R01'
passing h.msg
Columns
CA VARCHAR2(10) Path 'MSH/MSH.1',
CB VARCHAR2(30) Path 'MSH/MSH.7/TS.1',
) mI'm not familiar with XmlTable, but http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/img_text/xml_namespaces_clause.htm shows it should be zero or more "string AS prefix", and an optional "DEFAULT string" part. xmlns is not a valid namespace prefix (it's part of the XML Namespace Spec), so use another prefix (and use it in your XPath's), or try the DEFAULT expression, which sounds like it allows declaring the default namespace for the query.
So try either: elect m.*
from HA.Hl7_Messages h,
xmlTable
( XmlNamespaces('urn:hl7-org:v2xml' AS hv2),
'/hv2:ORU_R01'
passing h.msg
Columns
CA VARCHAR2(10) Path 'hv2:MSH/hv2:MSH.1',
CB VARCHAR2(30) Path 'hv2:MSH/hv2:MSH.7/hv2:TS.1',
) mor elect m.*
from HA.Hl7_Messages h,
xmlTable
( XmlNamespaces(DEFAULT 'urn:hl7-org:v2xml'),
'/ORU_R01'
passing h.msg
Columns
CA VARCHAR2(10) Path 'MSH/MSH.1',
CB VARCHAR2(30) Path 'MSH/MSH.7/TS.1',
) mNote that I'm making guesses here, as I haven't tried these. I hope this might help put you in the right direction though. --DD