From 4dfc4578548ea8f1bf69da5424d1e76a0b110a75 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 8 Aug 2010 19:15:27 +0000
Subject: [PATCH] Add an xpath_exists() function. This is equivalent to
XMLEXISTS except that it offers support for namespace mapping.
Mike Fowler, reviewed by David Fetter
---
doc/src/sgml/func.sgml | 92 +++++++++++++++++++----------
src/backend/utils/adt/xml.c | 26 +++++++-
src/include/catalog/catversion.h | 4 +-
src/include/catalog/pg_proc.h | 7 ++-
src/include/utils/xml.h | 3 +-
src/test/regress/expected/xml.out | 50 +++++++++++++++-
src/test/regress/expected/xml_1.out | 50 +++++++++++++++-
src/test/regress/sql/xml.sql | 12 +++-
8 files changed, 205 insertions(+), 39 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b981ca7f920..57b6f7aaa2a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.524 2010/08/05 18:21:17 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.525 2010/08/08 19:15:27 tgl Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
@@ -8175,7 +8175,7 @@ CREATE TYPE rainbow AS ENUM ('red', 'orange', 'yellow', 'green', 'blue', 'purple
linkend="datatype-xml"> for information about the <type>xml</type>
type. The function-like expressions <function>xmlparse</function>
and <function>xmlserialize</function> for converting to and from
- type <type>xml</type> are not repeated here. Use of many of these
+ type <type>xml</type> are not repeated here. Use of most of these
functions requires the installation to have been built
with <command>configure --with-libxml</>.
</para>
@@ -8231,7 +8231,7 @@ SELECT xmlcomment('hello');
<synopsis>
<function>xmlconcat</function>(<replaceable>xml</replaceable><optional>, ...</optional>)
</synopsis>
-
+
<para>
The function <function>xmlconcat</function> concatenates a list
of individual XML values to create a single value containing an
@@ -8277,18 +8277,18 @@ SELECT xmlconcat('<?xml version="1.1"?><foo/>', '<?xml version="1.1" standalone=
]]></screen>
</para>
</sect3>
-
+
<sect3>
<title><literal>xmlelement</literal></title>
-
+
<indexterm>
<primary>xmlelement</primary>
</indexterm>
-
+
<synopsis>
<function>xmlelement</function>(name <replaceable>name</replaceable> <optional>, xmlattributes(<replaceable>value</replaceable> <optional>AS <replaceable>attname</replaceable></optional> <optional>, ... </optional>)</optional> <optional><replaceable>, content, ...</replaceable></optional>)
</synopsis>
-
+
<para>
The <function>xmlelement</function> expression produces an XML
element with the given name, attributes, and content.
@@ -8375,18 +8375,18 @@ SELECT xmlelement(name foo, xmlattributes('xyz' as bar),
at which point a more precise description will appear.
</para>
</sect3>
-
+
<sect3>
<title><literal>xmlforest</literal></title>
-
+
<indexterm>
<primary>xmlforest</primary>
</indexterm>
-
+
<synopsis>
<function>xmlforest</function>(<replaceable>content</replaceable> <optional>AS <replaceable>name</replaceable></optional> <optional>, ...</optional>)
</synopsis>
-
+
<para>
The <function>xmlforest</function> expression produces an XML
forest (sequence) of elements using the given names and content.
@@ -8432,18 +8432,18 @@ WHERE table_schema = 'pg_catalog';
<function>xmlelement</function>.
</para>
</sect3>
-
+
<sect3>
<title><literal>xmlpi</literal></title>
-
+
<indexterm>
<primary>xmlpi</primary>
</indexterm>
-
+
<synopsis>
<function>xmlpi</function>(name <replaceable>target</replaceable> <optional>, <replaceable>content</replaceable></optional>)
</synopsis>
-
+
<para>
The <function>xmlpi</function> expression creates an XML
processing instruction. The content, if present, must not
@@ -8461,18 +8461,18 @@ SELECT xmlpi(name php, 'echo "hello world";');
]]></screen>
</para>
</sect3>
-
+
<sect3>
<title><literal>xmlroot</literal></title>
-
+
<indexterm>
<primary>xmlroot</primary>
</indexterm>
-
+
<synopsis>
<function>xmlroot</function>(<replaceable>xml</replaceable>, version <replaceable>text</replaceable> | no value <optional>, standalone yes|no|no value</optional>)
</synopsis>
-
+
<para>
The <function>xmlroot</function> expression alters the properties
of the root node of an XML value. If a version is specified,
@@ -8483,7 +8483,7 @@ SELECT xmlpi(name php, 'echo "hello world";');
<para>
<screen><![CDATA[
-SELECT xmlroot(xmlparse(document '<?xml version="1.1"?><content>abc</content>'),
+SELECT xmlroot(xmlparse(document '<?xml version="1.1"?><content>abc</content>'),
version '1.0', standalone yes);
xmlroot
@@ -8636,17 +8636,19 @@ SELECT xmlexists('//town[text() = ''Toronto'']' PASSING BY REF '<towns><town>Tor
<para>
To process values of data type <type>xml</type>, PostgreSQL offers
- the function <function>xpath</function>, which evaluates XPath 1.0
+ the functions <function>xpath</function> and
+ <function>xpath_exists</function>, which evaluate XPath 1.0
expressions.
</para>
<synopsis>
-<function>xpath</function>(<replaceable>xpath</replaceable>, <replaceable>xml</replaceable><optional>, <replaceable>nsarray</replaceable></optional>)
+<function>xpath</function>(<replaceable>xpath</replaceable>, <replaceable>xml</replaceable> <optional>, <replaceable>nsarray</replaceable></optional>)
</synopsis>
<para>
The function <function>xpath</function> evaluates the XPath
- expression <replaceable>xpath</replaceable> against the XML value
+ expression <replaceable>xpath</replaceable> (a <type>text</> value)
+ against the XML value
<replaceable>xml</replaceable>. It returns an array of XML values
corresponding to the node set produced by the XPath expression.
</para>
@@ -8657,13 +8659,13 @@ SELECT xmlexists('//town[text() = ''Toronto'']' PASSING BY REF '<towns><town>Tor
</para>
<para>
- The third argument of the function is an array of namespace
- 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
+ The optional third argument of the function is an array of namespace
+ mappings. This array should be a two-dimensional <type>text</> 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 (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
+ this array be the same as 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>
@@ -8671,7 +8673,7 @@ SELECT xmlexists('//town[text() = ''Toronto'']' PASSING BY REF '<towns><town>Tor
<para>
Example:
<screen><![CDATA[
-SELECT xpath('/my:a/text()', '<my:a xmlns:my="http://example.com">test</my:a>',
+SELECT xpath('/my:a/text()', '<my:a xmlns:my="http://example.com">test</my:a>',
ARRAY[ARRAY['my', 'http://example.com']]);
xpath
@@ -8682,7 +8684,7 @@ SELECT xpath('/my:a/text()', '<my:a xmlns:my="http://example.com">test</my:a>',
</para>
<para>
- How to deal with default (anonymous) namespaces:
+ To deal with default (anonymous) namespaces, do something like this:
<screen><![CDATA[
SELECT xpath('//mydefns:b/text()', '<a xmlns="http://example.com"><b>test</b></a>',
ARRAY[ARRAY['mydefns', 'http://example.com']]);
@@ -8691,6 +8693,36 @@ SELECT xpath('//mydefns:b/text()', '<a xmlns="http://example.com"><b>test</b></a
--------
{test}
(1 row)
+]]></screen>
+ </para>
+
+ <indexterm>
+ <primary>xpath_exists</primary>
+ </indexterm>
+
+<synopsis>
+<function>xpath_exists</function>(<replaceable>xpath</replaceable>, <replaceable>xml</replaceable> <optional>, <replaceable>nsarray</replaceable></optional>)
+</synopsis>
+
+ <para>
+ The function <function>xpath_exists</function> is a specialized form
+ of the <function>xpath</function> function. Instead of returning the
+ individual XML values that satisfy the XPath, this function returns a
+ boolean indicating whether the query was satisfied or not. This
+ function is equivalent to the standard <literal>XMLEXISTS</> predicate,
+ except that it also offers support for a namespace mapping argument.
+ </para>
+
+ <para>
+ Example:
+<screen><![CDATA[
+SELECT xpath_exists('/my:a/text()', '<my:a xmlns:my="http://example.com">test</my:a>',
+ ARRAY[ARRAY['my', 'http://example.com']]);
+
+ xpath_exists
+--------------
+ t
+(1 row)
]]></screen>
</para>
</sect2>
@@ -8698,7 +8730,7 @@ SELECT xpath('//mydefns:b/text()', '<a xmlns="http://example.com"><b>test</b></a
<sect2 id="functions-xml-mapping">
<title>Mapping Tables to XML</title>
- <indexterm zone="functions-xml-mapping">
+ <indexterm zone="functions-xml-mapping">
<primary>XML export</primary>
</indexterm>
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 6587f4e4fc9..520668cf400 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.99 2010/08/05 04:21:54 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.100 2010/08/08 19:15:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -3541,3 +3541,27 @@ Datum xmlexists(PG_FUNCTION_ARGS)
return 0;
#endif
}
+
+/*
+ * Determines if the node specified by the supplied XPath exists
+ * in a given XML document, returning a boolean. Differs from
+ * xmlexists as it supports namespaces and is not defined in SQL/XML.
+ */
+Datum
+xpath_exists(PG_FUNCTION_ARGS)
+{
+#ifdef USE_LIBXML
+ text *xpath_expr_text = PG_GETARG_TEXT_P(0);
+ xmltype *data = PG_GETARG_XML_P(1);
+ ArrayType *namespaces = PG_GETARG_ARRAYTYPE_P(2);
+ int res_nitems;
+
+ xpath_internal(xpath_expr_text, data, namespaces,
+ &res_nitems, NULL);
+
+ PG_RETURN_BOOL(res_nitems > 0);
+#else
+ NO_XML_SUPPORT();
+ return 0;
+#endif
+}
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 1decb54a99a..b4aeacb217e 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.592 2010/08/08 16:27:04 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.593 2010/08/08 19:15:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -53,6 +53,6 @@
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201008071
+#define CATALOG_VERSION_NO 201008081
#endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index bb8215c8fa8..812c65cb045 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.576 2010/08/08 16:27:04 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.577 2010/08/08 19:15:27 tgl Exp $
*
* NOTES
* The script catalog/genbki.pl reads this file and generates .bki
@@ -4415,6 +4415,11 @@ DESCR("evaluate XPath expression");
DATA(insert OID = 2614 ( xmlexists PGNSP PGUID 12 1 0 0 f f f t f i 2 0 16 "25 142" _null_ _null_ _null_ _null_ xmlexists _null_ _null_ _null_ ));
DESCR("test XML value against XPath expression");
+DATA(insert OID = 3049 ( xpath_exists PGNSP PGUID 12 1 0 0 f f f t f i 3 0 16 "25 142 1009" _null_ _null_ _null_ _null_ xpath_exists _null_ _null_ _null_ ));
+DESCR("test XML value against XPath expression, with namespace support");
+DATA(insert OID = 3050 ( xpath_exists PGNSP PGUID 14 1 0 0 f f f t f i 2 0 16 "25 142" _null_ _null_ _null_ _null_ "select pg_catalog.xpath_exists($1, $2, ''{}''::pg_catalog.text[])" _null_ _null_ _null_ ));
+DESCR("test XML value against XPath expression");
+
/* uuid */
DATA(insert OID = 2952 ( uuid_in PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2950 "2275" _null_ _null_ _null_ _null_ uuid_in _null_ _null_ _null_ ));
DESCR("I/O");
diff --git a/src/include/utils/xml.h b/src/include/utils/xml.h
index 6815e266c7c..807bb08485f 100644
--- a/src/include/utils/xml.h
+++ b/src/include/utils/xml.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/xml.h,v 1.32 2010/08/05 04:21:54 petere Exp $
+ * $PostgreSQL: pgsql/src/include/utils/xml.h,v 1.33 2010/08/08 19:15:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -37,6 +37,7 @@ extern Datum texttoxml(PG_FUNCTION_ARGS);
extern Datum xmltotext(PG_FUNCTION_ARGS);
extern Datum xmlvalidate(PG_FUNCTION_ARGS);
extern Datum xpath(PG_FUNCTION_ARGS);
+extern Datum xpath_exists(PG_FUNCTION_ARGS);
extern Datum xmlexists(PG_FUNCTION_ARGS);
extern Datum table_to_xml(PG_FUNCTION_ARGS);
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 439fef4877b..435331dcc37 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -502,7 +502,7 @@ SELECT xpath('//b', '<a>one <b>two</b> three <b>etc</b></a>');
{<b>two</b>,<b>etc</b>}
(1 row)
--- Test xmlexists evaluation
+-- Test xmlexists and xpath_exists
SELECT xmlexists('//town[text() = ''Toronto'']' PASSING BY REF '<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>');
xmlexists
-----------
@@ -515,6 +515,18 @@ SELECT xmlexists('//town[text() = ''Cwmbran'']' PASSING BY REF '<towns><town>Bid
t
(1 row)
+SELECT xpath_exists('//town[text() = ''Toronto'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
+ xpath_exists
+--------------
+ f
+(1 row)
+
+SELECT xpath_exists('//town[text() = ''Cwmbran'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
+ xpath_exists
+--------------
+ t
+(1 row)
+
INSERT INTO xmltest VALUES (4, '<menu><beers><name>Budvar</name><cost>free</cost><name>Carling</name><cost>lots</cost></beers></menu>'::xml);
INSERT INTO xmltest VALUES (5, '<menu><beers><name>Molson</name><cost>free</cost><name>Carling</name><cost>lots</cost></beers></menu>'::xml);
INSERT INTO xmltest VALUES (6, '<myns:menu xmlns:myns="http://myns.com"><myns:beers><myns:name>Budvar</myns:name><myns:cost>free</myns:cost><myns:name>Carling</myns:name><myns:cost>lots</myns:cost></myns:beers></myns:menu>'::xml);
@@ -543,6 +555,42 @@ SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beers/name[text() = ''Molso
1
(1 row)
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beer',data);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers',data);
+ count
+-------
+ 2
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers/name[text() = ''Molson'']',data);
+ count
+-------
+ 1
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beer',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 2
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers/myns:name[text() = ''Molson'']',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 1
+(1 row)
+
CREATE TABLE query ( expr TEXT );
INSERT INTO query VALUES ('/menu/beers/cost[text() = ''lots'']');
SELECT COUNT(id) FROM xmltest, query WHERE xmlexists(expr PASSING BY REF data);
diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index d15e50a1b9b..2ce543aeaa0 100644
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -456,7 +456,7 @@ LINE 1: SELECT xpath('//b', '<a>one <b>two</b> three <b>etc</b></a>'...
^
DETAIL: This functionality requires the server to be built with libxml support.
HINT: You need to rebuild PostgreSQL using --with-libxml.
--- Test xmlexists evaluation
+-- Test xmlexists and xpath_exists
SELECT xmlexists('//town[text() = ''Toronto'']' PASSING BY REF '<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>');
ERROR: unsupported XML feature
LINE 1: ...sts('//town[text() = ''Toronto'']' PASSING BY REF '<towns><t...
@@ -469,6 +469,18 @@ LINE 1: ...sts('//town[text() = ''Cwmbran'']' PASSING BY REF '<towns><t...
^
DETAIL: This functionality requires the server to be built with libxml support.
HINT: You need to rebuild PostgreSQL using --with-libxml.
+SELECT xpath_exists('//town[text() = ''Toronto'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
+ERROR: unsupported XML feature
+LINE 1: ...ELECT xpath_exists('//town[text() = ''Toronto'']','<towns><t...
+ ^
+DETAIL: This functionality requires the server to be built with libxml support.
+HINT: You need to rebuild PostgreSQL using --with-libxml.
+SELECT xpath_exists('//town[text() = ''Cwmbran'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
+ERROR: unsupported XML feature
+LINE 1: ...ELECT xpath_exists('//town[text() = ''Cwmbran'']','<towns><t...
+ ^
+DETAIL: This functionality requires the server to be built with libxml support.
+HINT: You need to rebuild PostgreSQL using --with-libxml.
INSERT INTO xmltest VALUES (4, '<menu><beers><name>Budvar</name><cost>free</cost><name>Carling</name><cost>lots</cost></beers></menu>'::xml);
ERROR: unsupported XML feature
LINE 1: INSERT INTO xmltest VALUES (4, '<menu><beers><name>Budvar</n...
@@ -517,6 +529,42 @@ SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beers/name[text() = ''Molso
0
(1 row)
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beer',data);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers',data);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers/name[text() = ''Molson'']',data);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beer',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 0
+(1 row)
+
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers/myns:name[text() = ''Molson'']',data,ARRAY[ARRAY['myns','http://myns.com']]);
+ count
+-------
+ 0
+(1 row)
+
CREATE TABLE query ( expr TEXT );
INSERT INTO query VALUES ('/menu/beers/cost[text() = ''lots'']');
SELECT COUNT(id) FROM xmltest, query WHERE xmlexists(expr PASSING BY REF data);
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index 4c88befc403..0e8c0fb2273 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -164,21 +164,29 @@ SELECT xpath('//text()', '<local:data xmlns:local="http://127.0.0.1"><local:piec
SELECT xpath('//loc:piece/@id', '<local:data xmlns:local="http://127.0.0.1"><local:piece id="1">number one</local:piece><local:piece id="2" /></local:data>', ARRAY[ARRAY['loc', 'http://127.0.0.1']]);
SELECT xpath('//b', '<a>one <b>two</b> three <b>etc</b></a>');
--- Test xmlexists evaluation
+-- Test xmlexists and xpath_exists
SELECT xmlexists('//town[text() = ''Toronto'']' PASSING BY REF '<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>');
SELECT xmlexists('//town[text() = ''Cwmbran'']' PASSING BY REF '<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>');
+SELECT xpath_exists('//town[text() = ''Toronto'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
+SELECT xpath_exists('//town[text() = ''Cwmbran'']','<towns><town>Bidford-on-Avon</town><town>Cwmbran</town><town>Bristol</town></towns>'::xml);
INSERT INTO xmltest VALUES (4, '<menu><beers><name>Budvar</name><cost>free</cost><name>Carling</name><cost>lots</cost></beers></menu>'::xml);
INSERT INTO xmltest VALUES (5, '<menu><beers><name>Molson</name><cost>free</cost><name>Carling</name><cost>lots</cost></beers></menu>'::xml);
INSERT INTO xmltest VALUES (6, '<myns:menu xmlns:myns="http://myns.com"><myns:beers><myns:name>Budvar</myns:name><myns:cost>free</myns:cost><myns:name>Carling</myns:name><myns:cost>lots</myns:cost></myns:beers></myns:menu>'::xml);
INSERT INTO xmltest VALUES (7, '<myns:menu xmlns:myns="http://myns.com"><myns:beers><myns:name>Molson</myns:name><myns:cost>free</myns:cost><myns:name>Carling</myns:name><myns:cost>lots</myns:cost></myns:beers></myns:menu>'::xml);
-
SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beer' PASSING data);
SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beer' PASSING BY REF data BY REF);
SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beers' PASSING BY REF data);
SELECT COUNT(id) FROM xmltest WHERE xmlexists('/menu/beers/name[text() = ''Molson'']' PASSING BY REF data);
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beer',data);
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers',data);
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/menu/beers/name[text() = ''Molson'']',data);
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beer',data,ARRAY[ARRAY['myns','http://myns.com']]);
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers',data,ARRAY[ARRAY['myns','http://myns.com']]);
+SELECT COUNT(id) FROM xmltest WHERE xpath_exists('/myns:menu/myns:beers/myns:name[text() = ''Molson'']',data,ARRAY[ARRAY['myns','http://myns.com']]);
+
CREATE TABLE query ( expr TEXT );
INSERT INTO query VALUES ('/menu/beers/cost[text() = ''lots'']');
SELECT COUNT(id) FROM xmltest, query WHERE xmlexists(expr PASSING BY REF data);
--
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