Database Software

I have some steps in Oracle to select the contents of an xml file, that work fine if all the tags and labels in the xml file match what I am looking for.
My problem is that sometimes someone will change one of the tags/labels in an xml file and not tell me. If that has happened, my select statement
does not return an error. If the XMLTABLE('/tblCageDuns/CageDuns' portion does not match the xml file (ex: instead of CageDuns, the xml file may
have CageDun), I get no rows returned. If one of the "columns" does not match (ex: instead of 'cage' the xml file may have 'cages'), I get a null
value for the column. Is there a way to read what all the tags and labels are in the xml file, so I can check them before I try to query the data?

Here are my basic steps:

1. Create a table with an XML column:

create table cagexml_col (
xmlfile_id number primary key,
xmlfile_doc XMLType);

2. Insert xml document:

insert into cagexml_col values (1,
XMLType(bfilename('ING_FEED', 'CAGEDUNS.xml'),
nls_charset_id('AL32UTF8')));

3. Read data:

select xmlfile_id,
a.CAGE,
a.DUNS,
a.SRCFLAG
FROM cagexml_col,
XMLTABLE('/tblCageDuns/CageDuns'
PASSING cagexml_col.xmlfile_doc
COLUMNS
CAGE VARCHAR2(5) Path 'cage',
DUNS VARCHAR2(9) Path 'duns',
SRCFLAG number Path 'SrcFlag'
) a
where xmlfile_id=1;



Here is a sample file CAGEDUNS.xml.

<tblCageDuns><CageDuns><cage>AAA87</cage><duns>111149236</duns><SrcFlag>0</SrcFlag></CageDuns><CageDuns><cage>BBB95</cage><duns>222245890</duns><SrcFlag>4099</SrcFlag></CageDuns><CageDuns><cage>CCC90</cage><duns>333368885</duns><SrcFlag>3</SrcFlag></CageDuns><CageDuns><cage>DDD14</cage><duns>444437379</duns><SrcFlag>3</SrcFlag></CageDuns><CageDuns><cage>EEE77</cage><duns>555597063</duns><SrcFlag>4097</SrcFlag></CageDuns><CageDuns><cage>FFF56</cage><duns>666639159</duns><SrcFlag>3</SrcFlag></CageDuns><CageDuns><cage>GGG95</cage><duns>777745890</duns><SrcFlag>4097</SrcFlag></CageDuns><CageDuns><cage>HHH16</cage><duns>888882310</duns><SrcFlag>3</SrcFlag></CageDuns><CageDuns><cage>III50</cage><duns>999987789</duns><SrcFlag>3</SrcFlag></CageDuns><CageDuns><cage>JJJ69</cage><duns>000073027</duns><SrcFlag>3</SrcFlag></CageDuns><CageDuns><cage>KKK77</cage><duns>121297063</duns><SrcFlag>4099</SrcFlag></CageDuns><CageDuns><cage>LLL68</cage><duns>232300000</duns><SrcFlag>3</SrcFlag></CageDuns></tblCageDuns>


Here is the version info:

**********************************************************************************
SQL*Plus: Release 10.2.0.1.0 - Production on Mon Oct 3 16:30:40 2011

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Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

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Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
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TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
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