I have just started using XML as I usually use php but I am trying to create a RSS feed so it is necesary. What is the best way of getting the data from my mysql database which I use with php that stores my blog? Is there anyway of using php inside of a XML document or would I have to do it using XML?
You are confused. XML is a format to store data, like .doc, .txt or .bmp (for image data).
If you want to get data from MySQL and put it in XML, you'll need a program that will do this for you.
You can use PHP to read the data from MySQL, and output it as XML or RSS.