XML Unleashed

Summary

This chapter examined the need for a query language for XML documents, and it looked at the general requirements for such a language and how they would differ from the requirements of a query language for a database. Specifically, an XML query language should be able to do the following:

• Describe hierarchical relationships.

• Describe sibling relationships.

• Return a well-formed XML document.

This chapter then looked at XQL, which is a language that meets these requirements. You then learned the salient points of the syntax of that language.

This chapter finished with a brief look at the implementation of XQL in XSL. Also, you learned about using the W3C DOM and hand-rolled functions for carrying out searches on XML documents.