From relational data stored on database servers to RDF files living on the web

The current web that we are using today, allows us to jump from one document to another, but in absence of semantic data. Meanwhile, the Semantic Web known as the ‘next generation’ of web full of linked and structured data gives us the chance to jump from one dataset to another, enriching the current web with more links and semantics. As we know, for various kinds of applications relational databases have been considered as one of the most popular storage solutions. While for the web of linked data they are recognized as a main factor in generating a huge amount of data. The process of mapping relational databases into ontologies is a fundamental problem on adapting the current web into the semantic one. Therefore, in this paper we are going to demonstrate the ways how we can publish data from relational databases into RDF through an approach that we find it very useful and then we will present the benefits, challenges and the solutions of the problems for mapping relational databases into ontologies and vice versa