Once a lesser-known category of software, databases have become a more and more important part of technical communication practice. Today databases often drive documentation collections, including content management systems and wikis. The most sophisticated databases tend to employ the SQL language.
Relational database systems (and the related standards body ANSI/INCITS H2) are busy adding XML support. One of the main components of such XML extensions will be support for the upcoming XML query language XQuery. The presentation will outline how XQuery and XML conceptually fit into a relational database environment. It will cover the organization of the XML in the database, how to type it using W3C XML Schema, how to query it both in conjunction with SQL and using top-level XQuery. It will present the concepts, talk about new developments in the ISO/ANSI SQL/XML standards and present some demos of XQuery in the upcoming Microsoft® SQL Server 2005.
XQuery speeds up the process of finding information contained in an XML document -- which is very handy when dealing with long XML documents. This article, the second of two parts, will teach you how to write XQuery expressions.