Beginning XML Databases (Wrox Beginning Guides)

Overview

XPath is used to navigate through XML documents, based on the absolute and relative position of a node in that XML document. Now that you know a thing or two about XPath, the next thing to examine is XQuery.

There are further steps beyond XPath and XQuery, such as XLink and XPointer, which will be covered in later chapters.

XQuery is to XML as SQL (Structured Query Language) is to relational databases. Simply put, XQuery is used to read XML documents. XQuery is designed to query anything appearing as XML data, even XML data type structures (or otherwise ) stored in a database.

There are no Try It Out sections in this chapter as the content here is primarily conceptual, but also introductory with respect to native XML database standards.

In this chapter you learn about:

• XQuery not written in XML

• Querying XML data using XQuery

• XPath and XQuery sharing a lot, including XPath functions

• Executing XQuery commands using Saxon

• Embedding of XQuery commands, HTML, and XML

• The FLWOR XQuery for loop

• Some specialized XQuery capabilities in Oracle Database as a part of Oracle XML DB