From b7f0be9a7e7ec1eb7b9780b169366495f24bf975 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Wed, 20 Jun 2018 12:58:12 -0400 Subject: [PATCH] Accept TEXT and CDATA nodes in XMLTABLE's column_expression. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Column expressions that match TEXT or CDATA nodes must return the contents of the nodes themselves, not the content of non-existing children (i.e. the empty string). Author: Markus Winand Reported-by: Markus Winand Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/0684A598-002C-42A2-AE12-F024A324EAE4@winand.at --- src/backend/utils/adt/xml.c | 24 ++++++++++++++---------- src/test/regress/expected/xml.out | 12 ++++++------ src/test/regress/expected/xml_2.out | 12 ++++++------ src/test/regress/sql/xml.sql | 4 ++-- 4 files changed, 28 insertions(+), 24 deletions(-) diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c index 7cdb87ef85..8307f1cf47 100644 --- a/src/backend/utils/adt/xml.c +++ b/src/backend/utils/adt/xml.c @@ -4508,11 +4508,21 @@ XmlTableGetValue(TableFuncScanState *state, int colnum, else if (count == 1) { xmlChar *str; + xmlNodePtr node; - str = xmlNodeListGetString(xtCxt->doc, - xpathobj->nodesetval->nodeTab[0]->xmlChildrenNode, - 1); + /* + * Most nodes (elements and even attributes) store their data + * in children nodes. If they don't have children nodes, it + * means that they are empty (e.g. ). Text nodes and + * CDATA sections are an exception: they don't have children + * but have content in the Text/CDATA node itself. + */ + node = xpathobj->nodesetval->nodeTab[0]; + if (node->type != XML_CDATA_SECTION_NODE && + node->type != XML_TEXT_NODE) + node = node->xmlChildrenNode; + str = xmlNodeListGetString(xtCxt->doc, node, 1); if (str != NULL) { PG_TRY(); @@ -4529,13 +4539,7 @@ XmlTableGetValue(TableFuncScanState *state, int colnum, } else { - /* - * This line ensure mapping of empty tags to PostgreSQL - * value. Usually we would to map a empty tag to empty - * string. But this mapping can create empty string when - * user doesn't expect it - when empty tag is enforced by - * libxml2 - when user uses a text() function for example. - */ + /* Ensure mapping of empty tags to PostgreSQL values. */ cstr = ""; } } diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out index 7fa1309108..3eb638ca25 100644 --- a/src/test/regress/expected/xml.out +++ b/src/test/regress/expected/xml.out @@ -1024,7 +1024,7 @@ SELECT xmltable.* PASSING data COLUMNS id int PATH '@id', _id FOR ORDINALITY, - country_name text PATH 'COUNTRY_NAME' NOT NULL, + country_name text PATH 'COUNTRY_NAME/text()' NOT NULL, country_id text PATH 'COUNTRY_ID', region_id int PATH 'REGION_ID', size float PATH 'SIZE', @@ -1046,7 +1046,7 @@ CREATE VIEW xmltableview1 AS SELECT xmltable.* PASSING data COLUMNS id int PATH '@id', _id FOR ORDINALITY, - country_name text PATH 'COUNTRY_NAME' NOT NULL, + country_name text PATH 'COUNTRY_NAME/text()' NOT NULL, country_id text PATH 'COUNTRY_ID', region_id int PATH 'REGION_ID', size float PATH 'SIZE', @@ -1075,7 +1075,7 @@ CREATE OR REPLACE VIEW public.xmltableview1 AS "xmltable".premier_name FROM ( SELECT xmldata.data FROM xmldata) x, - LATERAL XMLTABLE(('/ROWS/ROW'::text) PASSING (x.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) + LATERAL XMLTABLE(('/ROWS/ROW'::text) PASSING (x.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME/text()'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) EXPLAIN (COSTS OFF) SELECT * FROM xmltableview1; QUERY PLAN ----------------------------------------- @@ -1085,15 +1085,15 @@ EXPLAIN (COSTS OFF) SELECT * FROM xmltableview1; (3 rows) EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; - QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ + QUERY PLAN +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Nested Loop Output: "xmltable".id, "xmltable"._id, "xmltable".country_name, "xmltable".country_id, "xmltable".region_id, "xmltable".size, "xmltable".unit, "xmltable".premier_name -> Seq Scan on public.xmldata Output: xmldata.data -> Table Function Scan on "xmltable" Output: "xmltable".id, "xmltable"._id, "xmltable".country_name, "xmltable".country_id, "xmltable".region_id, "xmltable".size, "xmltable".unit, "xmltable".premier_name - Table Function Call: XMLTABLE(('/ROWS/ROW'::text) PASSING (xmldata.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) + Table Function Call: XMLTABLE(('/ROWS/ROW'::text) PASSING (xmldata.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME/text()'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) (7 rows) -- XMLNAMESPACES tests diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out index 112ebe47cd..cb865a9ef7 100644 --- a/src/test/regress/expected/xml_2.out +++ b/src/test/regress/expected/xml_2.out @@ -1004,7 +1004,7 @@ SELECT xmltable.* PASSING data COLUMNS id int PATH '@id', _id FOR ORDINALITY, - country_name text PATH 'COUNTRY_NAME' NOT NULL, + country_name text PATH 'COUNTRY_NAME/text()' NOT NULL, country_id text PATH 'COUNTRY_ID', region_id int PATH 'REGION_ID', size float PATH 'SIZE', @@ -1026,7 +1026,7 @@ CREATE VIEW xmltableview1 AS SELECT xmltable.* PASSING data COLUMNS id int PATH '@id', _id FOR ORDINALITY, - country_name text PATH 'COUNTRY_NAME' NOT NULL, + country_name text PATH 'COUNTRY_NAME/text()' NOT NULL, country_id text PATH 'COUNTRY_ID', region_id int PATH 'REGION_ID', size float PATH 'SIZE', @@ -1055,7 +1055,7 @@ CREATE OR REPLACE VIEW public.xmltableview1 AS "xmltable".premier_name FROM ( SELECT xmldata.data FROM xmldata) x, - LATERAL XMLTABLE(('/ROWS/ROW'::text) PASSING (x.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) + LATERAL XMLTABLE(('/ROWS/ROW'::text) PASSING (x.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME/text()'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) EXPLAIN (COSTS OFF) SELECT * FROM xmltableview1; QUERY PLAN ----------------------------------------- @@ -1065,15 +1065,15 @@ EXPLAIN (COSTS OFF) SELECT * FROM xmltableview1; (3 rows) EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; - QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ + QUERY PLAN +------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Nested Loop Output: "xmltable".id, "xmltable"._id, "xmltable".country_name, "xmltable".country_id, "xmltable".region_id, "xmltable".size, "xmltable".unit, "xmltable".premier_name -> Seq Scan on public.xmldata Output: xmldata.data -> Table Function Scan on "xmltable" Output: "xmltable".id, "xmltable"._id, "xmltable".country_name, "xmltable".country_id, "xmltable".region_id, "xmltable".size, "xmltable".unit, "xmltable".premier_name - Table Function Call: XMLTABLE(('/ROWS/ROW'::text) PASSING (xmldata.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) + Table Function Call: XMLTABLE(('/ROWS/ROW'::text) PASSING (xmldata.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME/text()'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text)) (7 rows) -- XMLNAMESPACES tests diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql index cb96e18005..c223603a1f 100644 --- a/src/test/regress/sql/xml.sql +++ b/src/test/regress/sql/xml.sql @@ -349,7 +349,7 @@ SELECT xmltable.* PASSING data COLUMNS id int PATH '@id', _id FOR ORDINALITY, - country_name text PATH 'COUNTRY_NAME' NOT NULL, + country_name text PATH 'COUNTRY_NAME/text()' NOT NULL, country_id text PATH 'COUNTRY_ID', region_id int PATH 'REGION_ID', size float PATH 'SIZE', @@ -362,7 +362,7 @@ CREATE VIEW xmltableview1 AS SELECT xmltable.* PASSING data COLUMNS id int PATH '@id', _id FOR ORDINALITY, - country_name text PATH 'COUNTRY_NAME' NOT NULL, + country_name text PATH 'COUNTRY_NAME/text()' NOT NULL, country_id text PATH 'COUNTRY_ID', region_id int PATH 'REGION_ID', size float PATH 'SIZE',