Selecting RSS feeds from a database

Pretty simple idea but a tough concept to grasp.

I would like to display like 3 rss feeds pulled from a database on my website.

They need to be pulled from a database because I want them to be displayed with stories on my website with similar content. So I would have a story table a category table and a rss table. I would have a cross reference table so I could display them where storyID = catID AND rssID = cat ID.

Any ideas of code that would simply select 3 rss feeds and display them.

If the SimplePie install could be adapted in some way that would be cool. I have it installed and have the Cache permissions set to 777.

Any help would be greatly appreciated. If you can’t supply code a website with some sort of rss feeds displayed from a database would be appreciated. I would like to display the feeds just from links in the database like http://rss.cnn.com/rss/cnn_topstories.rss