RDBToOnto allows to automatically generate fine-tuned OWL ontologies from relational databases.
A major feature of this full-fledged tool is the ability to produce structured ontologies with deeper hierarchies by exploiting both the database schema and the stored data.
RDBToOnto can be exploited to produce RDF Linked Data.
It can also be used to generate highly accurate RDB-to-RDF mapping rules (for D2RQ Server and Triplify).
An easy to use tool to create an ontology based on some relational data. It save the user for a lot of work by automation of the progress. The tool is a bit outdated in its relational drivers. Excel and Access seem to be outdated. MySQL works very well. The design is very simple with only the relevant features. The Original author is fast to repay to questions.