More clearly on XML namespaces inside xpath function

Thanks, applied.

---------------------------------------------------------------------------

Nikolay Samokhvalov wrote:

Explain how to deal with XML namespaces inside the "xpath" function
(especially about "default" namespaces, what is really unclear at first
glance).

Index: func.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/func.sgml,v
retrieving revision 1.516
diff -u -r1.516 func.sgml
--- func.sgml 3 Jun 2010 14:40:42 -0000 1.516
+++ func.sgml 4 Jun 2010 09:48:44 -0000
@@ -8596,8 +8596,11 @@
mappings.  This array should be a two-dimensional array with the
length of the second axis being equal to 2 (i.e., it should be an
array of arrays, each of which consists of exactly 2 elements).
-    The first element of each array entry is the namespace name, the
-    second the namespace URI.
+    The first element of each array entry is the namespace name (alias),
the
+    second the namespace URI. It is not required that aliases provided in
+    this array are the same that those being used in the XML document
itself (in
+    other words, both in the XML document and in the
<function>xpath</function>
+    function context, aliases are <emphasis>local</>).
</para>

<para>
@@ -8612,6 +8615,19 @@
(1 row)
]]></screen>
</para>
+
+   <para>
+    How to deal with default (anonymous) namespaces:
+<screen><![CDATA[
+SELECT xpath('//mydefns:b/text()', '<a xmlns="http://example.com
"><b>test</b></a>',
+             ARRAY[ARRAY['mydefns', 'http://example.com']]);
+
+ xpath
+--------
+ {test}
+(1 row)
+]]></screen>
+   </para>
</sect2>

<sect2 id="functions-xml-mapping">

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ None of us is going to be here forever. +