The un-queried life is not worth living
— Socrates (Plato, The Apology, 38a)
XQuery is a standardized language for combining documents, databases, Web pages and almost anything else. It is very widely implemented. It is powerful and easy to learn.
XQuery is replacing proprietary middleware languages and Web Application development languages. XQuery is replacing complex Java or C++ programs with a few lines of code. XQuery is simpler to work with and easier to maintain than many other alternatives.
The W3C XML Query Working Group worked with the W3C XML Schema Working Group and the W3C XSL Working Group to make a set of specifications that all work together.
Use XQuery to take data from multiple databases, from XML files, from remote Web documents, even from CGI scripts, and to produce XML results that you can process with XSLT.
Use XQuery on the back-end of a Web server, or to generate Enterprise-wide executive reports.
Submit your entry by sending mail to liam at w3.org, with [XQuery site] in the subject. Remember to give the full URL, and remember that it must be public.
Oxford African American Studies Center is a site published by Oxford University Press using an XQuery system. See the Site Credits link there for more details.
Alberta learning Center for education in the Canadian province of Alberta; e.g. see the Search link, which does not require registration.
AuthorMapper shows authors of scientific papers and articles broken down by geography and subject. The site is by Springer.
Business Week Business School Comparator is said to use XQuery to let users compare universities and business schools; it didn't seem to work for me, so maybe IE only? Or maybe I'm not cut out for business.
Business Exchange, another Business Week site, uses XQuery to drive a site where, it says, usiness professionals can collaborate and network around business topics.
CQ Legislative Impact is a tool to explore how pending US legislation might affect existing laws.
Data Request Broker, DRB, at Gael Consultant, is an open source Java API for processing heterogeneous data. It includes XQuery and Scema support. License is LGPL.
The Dolley Madison Digital Edition by the University of Virginia Press.
fromoldbooks.org has an image search engine powered by XML Query; you can see the text of the queries (follow the About link on the Search page). This is also used by Liam Quin's Photograph search page.
MarkMail is an XQuery-based application for searching and visualising mailing lists.
The New England Journal of Medicine uses XQuery to search and retrieve comprehensive case summaries and graphical icons that identify available supplemental content such as lab reports, radiological scans, histopathology slides, and photos associated with a particular case record.
O'Reilly Labs use XQuery to power code search, image search, statistics and more.
Pop Culture Universe is a Web site about American popular culture, including movies, books and music, with over 300 publications indexed and searchable.
Springer Images uses XQuery to search and retrieve scientific images, photos, tables, charts etc. for researchers.
Springer Exemplar provides a full-text interface to large numbers of scientific and technical journals, together with tools for narrowing down search results.
Wiley Custom Select is a Web site for creating custom course books.
Worldcolor has a custom publishing system using XQuery; they have a Flash demo.
Have you got a Web site that's powered by XML Query? A success story to share? Contact liam at w3.org.
There are over 40 different software packages that support XML Query in some way. Things to look for include availability of support, platforms, price, performance, all the usual issues, but you should also ask whether the software supports the final syntax from the W3C Recommendation or implements an earlier draft. Another XML Query specific feature is support for XML files, for fetching documents via HTTP, and for connecting to relational (or other) data sources: that is, whether the package lives up to the XML Query promise of unifying access to many different forms of information.
List of XQuery Implementations
There are some books listed; there are also people offering training and tutorials. If there is anything you found particular helpful, let us know!
There are also some mailing lists devoted to XML and to XML Query. You should look at the archives of each list before posting; you'll also need to subscribe to the list before you can post to it in most cases.
This is the W3C public mailing list on query languages, including (but not limited to) discussion on the XML Query project. Do not use this to send comments on the specification, such as errata or feature requests; see the Status section in each specification for instructions on how to send comments to the Working Group.
A mailing list hosted at x-query.com, especially for discussing XQuery.
Probably the most widely-known list for discussing XML.
W3C Specifications are aimed first and foremost at programmers writing implementations of them. We also try to make them readable for people trying to learn the language—but given a choice between making a standard precise and making it easy to read, we have to make it precise.
If you are fairly technical, you could start by reading the XML Query specification, and the XQuery Use Cases document has some examples. Many people would rather look for a book or tutorial.
Implementers: what would you most like to see here? What would have helped you the most?
The XQuery Test Suite was developed primarily to help the XML Query Working Group show that the specification could be implemented in such a way that queries would work on multiple systems - that is, interoperably. We are not currently doing active work on the test suite, but implementers continue to find it useful. It is not a conformance test suite: implementers are responsible for producing their own statements of conformance, and W3C does not have the resources to test or verify those statements.
There are additional test suites associated with XPath and XQuery.
— XQuery Update Facility 1.0 Test Suite
— XQuery and XPath Full Text 1.0 Test Suite (Joint)
XPath 2 has typed values; that is, the language associates a value type with each expression, variable or function. The set of possible types is that defined by W3C XML Schema, augmented by user-defined types derived from those basic Schema types using an external schema. The way in which an XPath or XQuery system derives and checks the type of an expression is defined formally, using a mathematical notation, in the XQuery 1.0 and XPath 2.0 Formal Semantics Recommendation.
Note that both external W3C Schema support and static typing are optional features, so not all implementations support them.
You will often see things in the specifications marked as being implementation defined. You must document what your implementation does for each of these.
The W3C XML Query Working Group has published a lot of documents. Many of these were done together with the XSL Working Group and are marked Joint.
Both of these Working Groups also met with the W3C XML Schema Working Group, to make sure our specifications all work together.
First, the main XML Query documents:
XQuery 1.0: An XML Query Language (W3C Recommendation)
XML Syntax for XQuery 1.0 (XQueryX) (W3C Recommendation)
XML Query (XQuery) 1.0 Requirements (W3C Working Group Note)
XML Query 1.0 Use Cases (W3C Working Group Note)
Building a Tokenizer for XPath or XQuery (Joint Note)
XSLT 2.0 shares a lot of the same functionality:
XSL Transformations (XSLT) Version 2.0 (by the XSL Working Group)
XQuery 1.0 and XSLT 2.0 both use XPath 2.0:
XML Path Language (XPath) 2.0 (W3C Recommendation; Joint)
XPath Requirements Version 2.0 (Joint)
XPath in turn is built on a number of Joint specifications :
XQuery 1.0 and XPath 2.0 Data Model (W3C Recommendation; Joint)
XSLT 2.0 and XQuery 1.0 Serialization (W3C Recommendation; Joint)
XQuery 1.0 and XPath 2.0 Formal Semantics (W3C Recommendation; Joint)
XQuery 1.0 and XPath 2.0 Functions and Operators (W3C Recommendation; Joint)
The XML Query and XSL Working Groups are developing Full-Text Search for XPath 2.0 and, of course, XQuery 1.0; when finished, this will then be available for use in XQuery and XSLT:
The XML Query Working Group is developing an update facility for XQuery; this lets you write Query expressions that change documents and perhaps save the result.
The XML Query Working Group is working on the next version of XML Query, XQuery 1.1.
The XML Query Working Group is working on Scripting Extensions for XQuery. The goal is to investigate whether adding imperative (procedural) features such as variable assigment and explicit sequencing to XQuery makes the language significantly more powerful or easier to use.
Send your XQuery-related news item to liam@w3.org, with [XQuery] in the Subject. Note, I am sorry that sometimes I miss announcements. I get hundreds, sometimes thousands, of messages in a day. If your announcement does not appear within one week, send it again and please accept my apologies!
BaseX 7.0.01 has been released; BasX 7 can store fils of any format, is said to be faster, includes support for JSON, accessing SQL databases, digital signagures, and more language support for Full Text searching.
W3C Java Applets have been updated to incorporate the latest versions of the specifications for the XPath and XQuery 3.0 drafts as well as for the 1.0 documents.
XQSharp 2.0 released. This version brings full XSLT 2.0 support to the .NET Framework. XQSharp is an XSLT 2.0 and XQuery 1.0 processor for the .NET Framework.
BaseX 6.5 has been released; many new features from the XQuery 3.0 draft, Full Text, function libraries, text compression, enhanced collection suppoer.
OxygenXML released <oXygen> XML Editor and Author version 12.1, with improvements to XQuery and XSLT debuggers, including XSLT 2.0 and XQuery Types in Variables and XWatch Views and enhanced XSLT Context Information., amongst many other changes.
Qizx 4.1 includes more of the features from the draft for XQuery 1.1 [now called XQuery 3.0], support for non-XML documents, and can store over 1,000 Gigabytes of XML.
CBCL Released XQSharp 1.5 which includes large performance improvements especially for recursive functions.
Zorba 1.4 (XQuery Processor) has been released. This release comes with an extended function library and support for the [draft] XQuery 1.1 switch expression.
XDIB (XQuery In a Browser) is a build of the Firefox Web browser that incorporated XQuery support using sedna.
Qizx 4.0 is now available; new features include HTTP server, some initial scripting support, and XQuery Services.
W3C Java Applets have been updated to incorporate the latest versions of the specifications for XPath 2.1, XQuery 1.1, Full Text and Update.
BaseX 6.0 has been released. New features include an implementation of XQuery Update, enhanced client/server architecture and extended XQuery Full Text features
IBM announced support for XPath 2.0, XSLT 2.0, and XQuery 1.0 via the WebSphere Application Server V7.0 Feature Pack for XML 1.0.0.0 - IBM says that this release fully supports the W3C standards, introduces a Java API that unifies all three languages, and is optimized for performance and reliability in application server environments. See also the WebSphere announcement.
Cognetic Systems - XQuantum Server 1.50 - released for Windows and Linux Features include XQuery 1.0 conformance, static typing, query modules, and full-text search based on a subset of the draft standard. The server uses XML indexing and query optimization to access large XML data stores.
Cognetic Systems say they have released a beta version of XQuantum 1.5, with some full-text support, static typing, and modules.
An XQJ driver for Sedna has been released, conforming to the XQuery API for Java Test Compatibility Kit.
CBCL UK has released XQSharp for the .NET framework. All optional XQuery 1.0 features are supported, including modules, static typing, full namespace axis and schema import.
BaseX 5.7 has been released. New features include support for the XQuery Full Text draft, improved XQuery and index performance, enhanced XQuery editing facilities and improved client/server stability
Qizx 3.0 is now available, with XQuery Full-Text support as well as speedups and memory improvements.
Qizx Beta 3 is now available. new features include extensive Full-Text support as well as performance enhancements.
XBird light-weight embeddable open source Java implementation added to the list of implementations.
BaseX 5.0 has been released. New features include Full-Text support, improved XQuery conformance, XQJ (XQuery for Java) and XAPI (XML:DB) APIs, as well as GUI improvements for interactions and visualizations.
Qizx Free Engine and Qizx/open 2.2 released; Qizx is an embeddable, high-speed, native XML index-based XML Query engine written in the Java language. New features in 2.2 include support of the draft XQuery 1.1 group by and for . . . window features, and a more liberal licensing scheme. The source code is also now available for purchase.
oXygen XML Editor and Author version 10.0 has been released, and now includes the schema-aware XSLT 2.0 and XQuery processor from Saxonica, a new XML instance generator, tag completion based on schemas and XSLT stylesheets, integration of the Intel XML Software Suite, and more. Supports MarkLogic 4.0, Oracle 11g R1, SQL Server 2008, DB2 9.5, XHive 8, and Subversion 1.5.
MarkLogic announced their MarkLogic Server 4.0, inlcuding full support for XQuery 1.0 as well as the draft Update and Full-Text specifications. New features include geospatial search, additional content analytics, alerting, and entity extraction.
The W3C XML Query Working Group has released a First Public Working Draft of XQuery 1.1.
W3C Recommendation Status for XQuery 1.0: An XML Query Language, XML Syntax for XQuery 1.0 (XQueryX) and XML Path Language (XPath) 2.0, as well as the supporting specifications, XQuery 1.0 and XPath 2.0 Functions and Operators, XQuery 1.0 and XPath 2.0 Data Model (XDM), XSLT 2.0 and XQuery 1.0 Serialization and of course XQuery 1.0 and XPath 2.0 Formal Semantics. In addition, XSL Transformations (XSLT) Version 2.0 by the XSL Working Group is also a W3C Recommendation.
oXygen editor 8.0 includes debugging support for both XML Query and XSLT, with support for Berkeley XML DB, IBM DB2 Pure XML, eXist XML Database, MarkLogic, Microsoft SQLServer 2005, Oracle 10g R2, RainingData TigerLogic XDMS, SoftwareAG Tamino and XHive XML Database.
The XML Query Working Group operates under the Royalty Free terms of the W3C Patent policy. Patent disclosures relevant to the specifications produced by the XML Query working group can be found in the Implementation of the W3C Patent Policy (IPP) XML Query IPP status page and, for XSL and joint specifications the XSL WG IPP status page. Older disclosures are on the XML Query Working Group's patent disclosure page at http://www.w3.org/2002/08/xmlquery-IPR-statements.
Specifications that are joint work with the XSL working group have also the additional patent disclosures provided by the XSL wg at http://www.w3.org/Style/XSL/Disclosures.
Note: before posting to this mailing list, be sure to read the Status section in the document on which you are commenting. Most of our documents now ask you to send comments using bugzilla.
This public mailing list is used to submit comments on the publications of the XML Query and XSL working groups. This is not a discussion list (use www-ql@w3.org instead), and so you shouldn't subscribe: this list is just a way for people to provide their comments to the XML Query and XSL WGs, and for the WGs to reply. The list is publicly archived at http://lists.w3.org/Archives/Public/public-qt-comments/.
If your implementation is not here, or if you know of an implementation that is not listed, send liam@w3.org the details!
Software that implements the XQuery 1.0 and XPath 2 Full Text Facility is so marked in this list. There is a separate list of XPath 2 implementations.
Please send liam@w3.org any information about these; I have tried to contact people where possible.
Software that implements XPath 2.0, but not XML Query or XSLT 2
The following is a (non-comprehensive) list of announcements of products that will include some support for XQuery, or that are of related nature:
I have tried to indicate where authors participated in the XML Query Working Group, sent comments on the specifications, or have written implementations themselves. This does not necessarily make them good writers, but it may help you to understand their point of view and their connection with XML Query.
Books that I have received more recently are at the top of the list.
An XQuery Wikibook by Chris Wallace, Dan Mcreary and Kurt Cagle
Querying XML : XQuery, XPath, and SQL/XML in context by Jim Melton and Stephen Buxton; The Morgan Kaufmann Series in Data Management Systems, 2006. The book also has its own Querying XML Web page. [Both authors have participated heavily in the development of XML Query; Jim Melton is currently the co-chair of the W3C XML Query Working Group. - Liam]
XQuery: The XML Query Language by Michael Brundage; Addison-Wesley Professional, February 2004. With a foreword by Michael Rys. Book web site at www.qbrundage.com/xquery/. [The first half of the book is an introduction to XQuery, including an interesting chapter on Idioms. The second half is a reference. - Liam]
XQuery from the Experts edited by Howard Katz, with chapters by Don Chamberlin, Denise Draper, Mary Fernandez, Michael Kay, Jonathan Robie, Michael Rys, Jerome Simeon, Jim Tivy and Philip Wadler. Addison-Wesley Professional, September 2003. There are two chapters online at www.fatdog.com. [Although this book is older, the text is a very happy mix of tutorials, design rationale and examples. The authors have been heavily involved in the design of XML Query, and most have been active memebers of the W3C XML Query Working Group; the editor, Howard Katz, has also made his own open-source implementation. - Liam]
I have not seen the following books:
XQuery Kick Start by James McGovern, Per Bothner, Kurt Cagle, James Linn and Vaidyanathan Nagarajan; Sams, September 2003. [I have not seen this book. Per Bothner made many helpful public comments on the specifications - Liam]
Early Adopter XQuery by Dan Maharry, Rogerio Saran, Kurt Cagle, Mark Fussell and Nalleli Lopez. Wrox Press; January, 2002. [This book was probably too early to be of use today, although I have not seen it to be sure. I am listing it for completeness. Michael Brundage has written that it is out of date, but that it reviewed some XQuery APIs - Liam]
Querying XML with XQuery (Advances in Database Systems) by Yannis Papakonstantinou and Ioana Manolescu. Springer; March 2006 [forthcoming, I assume. Ioana participates in the XML Query Working Group. - Liam]
XQuery - Grundlagen und fortgeschrittene Methoden by Wolfgang Lehner. dpunkt.verlag, January 2004; this book is downloadable from Amazon for US$30.
A Google search for "(XQuery tutorial"|"XML Query tutorial") produced over 150 matches (Google actually said about 30,500 but this turned out to mean exactly 153).
To suggest a new pointer, send an email to member-query-feedback@w3.org.
To contact the XML Query and XSL Working Groups, you can send email to public-qt-comments at w3.org
To report errors in the specification please use bugzilla, as described in the Status section at the start of each specification.
To comment on this page, send mail to liam at w3 dot org
First created by Massimo Marchiori on April 2000.