Looking at SDOs and their associated interface, you should get a clear idea of the API the SDO extension provides. We then move on to show a working example of using SDOs in a two-part application comprising a small PHP application to implement a simple Web log (blog) and a part that displays that blog as an RSS feed. Both parts use SDOs as a way of working with XML. We hope you will agree that SDO is an attractive option for working with XML data in PHP.
In part one, they get down to basics and introduce what the service data objects are, how they work, what they look like, and what kind of options they offer. Near the end, they start talking some about the XML structure in preparation for the next part.
Part two picks up right where the previous part left off, taking the basic knowledge and building on it, showing how to create an SDO, and add the namespaces needed. From there, for the sake of time, they give a simple blogging application for download to illustrate how the pieces fit together. They break apart the pieces, showing what each part does and demonstrate how to add entries to the blogging application.