How to parse an XML file from a url and add its data in a database?

[eluser]bretticus[/eluser]
XML-RPC is meant more as a system for a Web service (think SOAP or REST.) In other words, requests from the client will be interpreted as code calls on the server. The server will then return the results of the code ran. Not really what you are doing.

PHP has an excellent extension called SimpleXML. It basically maps an XML document to an object that is easy to traverse.

UPDATE

I see you are using SimpleXML already. My advice about XML-RPC still stands and you should follow the documentation for SimpleXML to parse it. See SimpleXML Examples.