Querying Relational Database in Semantic Web

Abstract

The advent of the World Wide Web (WWW) has taken the availability of information to an unprecedented level. The rapid growth of the web poses new problems. The next generation of Web is expected to be the Semantic Web. The vision of the Semantic Web is to give data on the web a well defined meaning by representing it in languages like RDF and OWL and linking it to commonly accepted ontologies. Although information necessary for daily work is readily accessible over internet via various search engines, the current infrastructure for managing information is not well suited for information-oriented activities. Information and functionality is scattered across applications and websites, making it difficult to aggregate and reuse just the right set of content and operations required for unique user tasks. As the Semantic Web has matured, it has become clear that there is a need to integrate older technologies. One such technology is relational databases. Most formatted data today is stored in relational databases. To be able to use relational databases data on the Semantic Web, we need a flexible but easy to use mechanism to map relational data into RDF or OWL. In this thesis the intent is to enable Semantic access to Relational Database using D2R mapping and JENA API. D2R mapping language performs mapping between relational database schemata and RDF and then JENA (a Java query engine) is used to manipulate RDF data as SQL server is used for Relational data.