The lib_mysqludf_xql library provides an array of functions, 
which can be used to create XML output directly from MySQL 
using a single SQL query. This prevents having to convert a 
MySQL result to XML in a PHP script, Ruby script, etc. 

The library provides the same functionality as SQL/XML, seen 
in MS SQL server and Oracle. However it uses normal functions. 
By using subqueries the same results as SQL/XML can be generated. 

WWW: http://www.mysqludf.org/lib_mysqludf_xql/index.php