XQuery Kick Start

Chapter 2. Understanding the XPath 2.0 Specification

by Kurt Cagle

IN THIS CHAPTER

• In Search of Context: XQuery and XPath

• The Need for XPath

• Directories and Nodes

• XPath 1.0

• XPath 2.0's New Features

• Understanding Sequences

• Handling Aggregate Functions

• The tokenize() Function

• Working with External Resources

• Cutting Verbosity with XPath Command Structures

• Regular Expressions

• Of Data Types and Dates

• In Brief

In Search of Context: XQuery and XPath

XPath originally emerged at the intersection of XLink (which defines a method of using URLs to describe locations within a document) and XSLT, which provides XML transformations based upon some demonstrable set of patterns. As will be explained later in this chapter, XPath provided a way of extracting pieces of the tree ...