Summary

The purpose of this hour was to introduce the concepts behind relational databases and explain how to integrate them with your XML applications. First, I provided a brief introduction to the theory behind relational databases, which is important to understand when you're mixing them with a different sort of data structure, like the one provided by XML. I then provided a very brief overview of SQL, which is the language used to query all relational databases. I then described the issues that arise when you're integrating relational databases with XML applications, and explained how using XML for data storage and XML as a document format differ. Finally, I demonstrated how to export XML data from an existing database, as well as how to perform a SQL query on a database and format the results as an XML document.