"takes an sql-query, a pear::db_result or an array and gives you back a xml string or object representing the data. You get a more or less decent result with just the basic settings, but it's also highly configurable, so you can almost get what you want. And furthermore, if you have joined queries, this class tries to detect the relationship and gives you back a nested xml out of that. This does not always work right, but you can customize the relationship between the tables, as well. The automatic relationship detection does only work with mysql at the moment. But the class itself can be used with any db supported by the pear database abstraction class." via
more like this