What is a good internet tutorial on learning AJAX and database management?

Here are some good learning pages and tutorials for AJAX and databases:





Creating a MySQL connection with PHP/AJAX:


http://www.johnwiseman.ca/blogging/?p=61





Building an AJAX-Based Chat: Interacting With a Database:


http://www.devarticles.com/c/a/XML/Build鈥?/a>





Very Dynamic Web Interfaces:


http://www.xml.com/pub/a/2005/02/09/xml-鈥?/a>





XML in the Browser: Submitting forms using AJAX:


http://tinyurl.com/9jx59/XML-in-the-Brow鈥?/a>





How to Use AJAX:


http://www.informit.com/articles/article鈥?/a>





A Simpler Ajax Path:


http://www.onlamp.com/pub/a/onlamp/2005/鈥?/a>