Working with XMLTABLE, problem extracting data where elements have no prefixes/namespaces - response (1) by mikemadrinan

Ok, after some experimentation, I think I fixed the issue... As I've mentioned, the above code is just mocked code I prepared for the purpose of demonstrating my issue.  There is actually a defined default namespace.  The real XML is closer to the the sample below:

<pfx:MAIN xlmns:pfx="http://www.google.com/" xlmns="http://www.yahoo.com/">
  <pfx:header>
    <pfx:name>sample</pfx:name>
    <pfx:value>1</pfx:value>
  </pfx:header>
  <pfx:payload>
    <portfolio>
      <portfolioname>A</portfolioname>
      <portfoliovalue>100</portfoliovalue>
    </portfolio>
  </pfx:payload>
</pfx:MAIN>

Experimenting, I tried adding the default namespace in the XMLNAMESPACES to see if it would fix the problem but the query still returned NULL for the portfolioname and portfoliovalue.  I tried a few permutations to try and fix problem but what helped was when I forced a prefix on the default namespace. (see below):  

SELECT PORTFOLIO.*
FROM  (SELECT * FROM XML_TABLE WHERE xml_ID = 1) AS XML_ROW,
        XMLTable(
      XMLNAMESPACES('http://www.google.com' AS "X",
                    'http://www.yahoo.com' AS "Y"),
      '/' PASSING XML_ROW.XML_DATA
      COLUMNS
         "name" VARCHAR(100) PATH 'X:MAIN/X:header/X:name'
        ,"value" VARCHAR(100) PATH 'X:MAIN/X:header/X:value'
        ,"portfolioname" VARCHAR(100) PATH 'X:MAIN/X:payload/Y:portfolioname'
        ,"portfoliovalue" VARCHAR(100) PATH 'X:MAIN/X:payload/Y:portfoliovalue'
    ) AS PORTFOLIO

Note that I did not change the source XML, only the query.  This worked, though I haven't been able to figure out why.  It maybe due to some issues with the handling on the namespace in the background.
I hope this helps.