Web Services using Yii

Hi,

I want to create a web service which takes data from an external database which would be in XML format and stores in the local database. I tried the example

http://www.yiiframework.com/doc/guide/1.1/en/topics.webservice , it works. I want to know how can i use it here?

Actually i have not worked on web services before so please guide me.

Thanks

I opted to use php instead :-[