xml2

XPath querying and XSLT
Repository
https://www.postgresql.org/docs/current/xml2.html
https://www.postgresql.org/docs/current/xml2.html

Overview

PackageVersionCategoryLicenseLanguage
xml21.1TYPEPostgreSQLC
IDExtensionBinLibLoadCreateTrustRelocSchema
3990xml2NoNoNoYesNoNo-
Relatedpgjq prefix semver unit pgpdf pglite_fusion md5hash asn1oid

Version

PG18PG17PG16PG15PG14
1.11.11.11.11.1

Install

Note: This is a built-in contrib extension of PostgreSQL

CREATE EXTENSION xml2;

Usage

xml2: XPath querying and XSLT functionality

The xml2 extension provides XPath querying and XSLT transformation functions for XML documents. Note: this module is deprecated in favor of the core SQL/XML functionality.

CREATE EXTENSION xml2;

XML Validation

SELECT xml_valid('<doc><item>test</item></doc>');  -- true

XPath Query Functions

-- Extract text value
SELECT xpath_string('<doc><name>Alice</name></doc>', '/doc/name');

-- Extract numeric value
SELECT xpath_number('<doc><count>42</count></doc>', '/doc/count');

-- Extract boolean
SELECT xpath_bool('<doc><active>true</active></doc>', '/doc/active');

-- Extract node set with tags
SELECT xpath_nodeset('<doc><a>1</a><a>2</a></doc>', '/doc/a', 'results', 'item');

-- Extract values as comma-separated list
SELECT xpath_list('<doc><a>1</a><a>2</a></doc>', '/doc/a');  -- 1,2

xpath_table Function

Evaluate multiple XPath queries across a set of documents:

SELECT * FROM
  xpath_table('id', 'xml_col', 'documents',
              '/doc/author|/doc/title',
              'true')
  AS t(id int, author text, title text);

Parameters:

  • Key field name (first output column)
  • XML document field name
  • Table/view name
  • XPath expressions separated by |
  • WHERE clause (use 'true' for all rows)

XSLT Transformation

-- Apply XSL stylesheet to document
SELECT xslt_process(xml_document, xsl_stylesheet);

-- With parameters
SELECT xslt_process(xml_document, xsl_stylesheet, 'param1=value1,param2=value2');

Last Modified 2026-03-12: add pg extension catalog (95749bf)