Using a database to dynamically create web pages makes for a much improved site in many ways. However, such URLs are not very search engine friendly. Search engines are much better at indexing static pages, and don't do a good job of following hyperlinks that contain query strings. The advantages of a dynamic site are overwhelmingly obvious--so what is to be done? With a little extra effort, you can create a dynamic site that is easily crawled by webbots.
Make Dynamic URLs Search Engine Friendly (Page 1 of 7 )
The robots used by search engines have problems with dynamic pages. You may review Google’s comments on this subject at http://www.google.com/webmasters/2.html.
However, dynamic URLs can be converted into static URLs so that they can be indexed. For example, the dynamic URL