Add an xpath_exists() function. This is equivalent to XMLEXISTS except that

it offers support for namespace mapping.

Mike Fowler, reviewed by David Fetter

3 files changed, 108 insertions, 4 deletions

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);