How can I use ontologies and SWRL in a recommendation application?

I'm working on a new project for recommendations to illustrate the importance of the semantic web. So, I decided to use ontologies and SWRL rules. But I have questions, does the ontology replace the role of the database (i.e. should I use only ontologies or should I use for example MySQL with ontology)? And what is the role of SWRL in the project?