The Web is replete with databases, many of which are modeled on the relational paradigm. Currently, for the purpose of simultaneous querying data from multiple databases, the federated database technique is used extensively. However, the effectiveness of such a technique is suspect when it comes to querying heterogeneous databases. Therefore, it becomes imperative to develop an efficient methodology for the semantic integration of heterogeneous online databases. This may be realized by defining a mapping from a relational database to a description that utilises the Resource Description Framework (RDF). Such a representation would be machine processable and would make the semantics as expressed by databases more explicit and, thereby, facilitate their integration.