XQuery Candidate Recommendation Documents Released

The official candidate recommendation versions of the XQuery specifications have been published by the W3C at http://www.w3.org/TR/#CR. The details of the specific documents are as follows: XQuery 1.0: An XML Query Languagehttp://www.w3.org/TR/2005/CR-xquery-20051103/ XQuery 1.0 and XPath 2.0 Functions and Operatorshttp://www.w3.org/TR/2005/CR-xpath-functions-20051103/ XQuery 1.0 and XPath 2.0 Data Model (XDM)http://www.w3.org/TR/2005/CR-xpath-datamodel-20051103/ XQuery 1.0 and XPath 2.0 Formal Semanticshttp://www.w3.org/TR/2005/CR-xquery-semantics-20051103/…


Dynamic XQuery Expressions

We have had several requests through our message boards for details on how to execute dynamic XQuery expressions. A dynamic XQuery expression is one whose exact details are not know at the time when the query is written. For example, consider the following XML fragment stored in a single XML data-type instance:<foo id=”1″>foo 1</foo> <foo…


XQuery Test Suite – new version 0.7 released

The XQuery Testing Task Force is pleased to announce the publication of version 0.7 of our XQuery test suite. Please visit http://www.w3.org/XML/Query/test-suite/ for details.


Static Typing Consequences for the Parent Axis and Attribute Types

I posted a previous blog entry dealing with the static typing consequences of using the parent axis in your XQuery expressions over XML data inside SQL Server 2005 (Static Typing Consequences of the Parent Axis). In addition to the general issue of typing information loss associated with the parent axis, there is an additional issue…


XML Data-type Usage By Other SQL Server 2005 Features

Several of the other features within SQL Server 2005 leverage the XML data-type to pass information around. For example, both Service Broker and triggers transfer data around the server in XML data-type instances. This means that you can easily leverage the power of the XQuery language and other XML data-type methods when using these features….


Static Typing Consequences of the Parent Axis

SQL Server 2005 has an XQuery implementation that provides full support for the parent axis, as defined in the XPath specification. Since our XQuery implementation is statically typed, we also support the static typing of the parent axis, as defined in the XQuery Formal Semantics document. The definition of static typing of the parent axis…


XML Query Test Suite – version 0.6 released

The W3C XQuery Testing Task Force (of which I am a member) has released version 0.6 of the XML Query Test Suite. This is currently available at http://www.w3.org/XML/Query/test-suite/. The test suite consists of XQuery expressions, results and source files that test various different aspects of an XQuery implementation against the latest published drafts of the…


Querying Over Constructed XML Using Sub-queries

There are a number of cases where it would be useful to be able to run XQuery statements over the result of an XQuery expression which constructs new values. Unfortunately, directly querying over constructed XML is not supported in SQL Server 2005, so we need to use a work-around. Since the result of a query()…


Working with XML from Multiple Instances

There are often cases where we need to perform operations based on multiple XML instances. To illustrate this, consider the example XML given below. Basically, we have two XML instances. The first instance (call this the results instance) contains information about the execution of a set of tests. Each test entry contains a name for…


Namespace Nuances

XQuery uses the concept of a namespace, adopted from the XML 1.0 specification. But, due to the complex nature of the XQuery language and it’s dual roles as both query and serialization/XML construction language, there are several nuances to the use of namespaces that may not be immediately obvious. The first issue I will deal…