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<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
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- project.
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- Copyright (C) 1998-2018 OpenLink Software
-
- This project is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by the
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- 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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-->
<refentry id="fn_XMLType.existsNode">
<refmeta>
<refentrytitle>XMLType.existsNode</refentrytitle>
<refmiscinfo>xml</refmiscinfo>
</refmeta>
<refnamediv>
<refname>XMLType.existsNode</refname>
<refpurpose>Tests node existence having evaluated given XPATH expression.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis id="fsyn_XMLType.existsNode">
<funcprototype id="fproto_XMLType.existsNode">
<funcdef><function>XMLType.existsNode</function></funcdef>
<paramdef>in <parameter>xpath_expn</parameter> varchar</paramdef>
<paramdef><optional>in <parameter>namespace_map</parameter> varchar</optional></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 id="desc_XMLType.existsNode">
<title>Description</title>
<para>The member function calculates the given XPATH expression <parameter>xpath_expn</parameter> using
the XML entity of the instance as a context node. If a <parameter>namespace_map</parameter> parameter
is given then the function adds namespace declarations from this parameter into the beginning of
<parameter>xpath_expn</parameter> before the evaluation.
The function returns 1 if the first result of XPATH evaluation is a node or 0 if there are no results or if the first result is not a node.
</para>
</refsect1>
<refsect1 id="params_XMLType.existsNode">
<title>Parameters</title>
<refsect2><title>xpath_expn</title>
<para>A text of XPATH expression to evaluate.</para>
</refsect2>
<refsect2><title>namespace_map</title>
<para>A string that is a list of namespace prefix declarations delimited by whitespace characters.
If the <parameter>xpath_expn</parameter> expression also contains a list of declarations then these two
lists are concatenated.</para>
</refsect2>
</refsect1>
<refsect1 id="ret_XMLType.existsNode"><title>Return Types</title>
<para>The function returns integer 1 or 0</para>
</refsect1>
<refsect1 id="examples_XMLType.existsNode">
<title>Examples</title>
<example id="ex_XMLType.existsNode"><title>A table with an XMLType column</title>
<para>This populates a table with XML data and then reports which rows contain 'empno' element inside 'emp'.</para>
<screen><![CDATA[
create table TEST_XMLS (I integer primary key, XMLVAL XMLType);
insert into TEST_XMLS values (1, XMLType('<emp><empno>221</empno><ename>John</ename></emp>'));
insert into TEST_XMLS values (2, XMLType('<po><pono>331</pono><poname>PO_1</poname></po>'));
insert into TEST_XMLS values (3, XMLType('<oil-rig id="14a" water="0.413"/><oil-rig id="14b" water="0.402"/>'));
select e.I, e.XMLVAL.existsNode('/emp/empno')
from TEST_XMLS as e
I callret
INTEGER NOT NULL INTEGER
_______________________________________________________________________________
1 1
2 0
3 0
3 Rows. -- 00000 msec.
]]>
</screen>
</example>
</refsect1>
<refsect1 id="seealso_XMLType.existsNode">
<title>See Also</title>
<para><link linkend="fn_XMLType.extract"><function>XMLType.extract()</function></link></para>
</refsect1>
</refentry>
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