Computer Science Department, Technion - Israel Institute of Technology, Haifa, Israel
The popular open source RDB to RDF mapping platform - D2RQ provides only a read-only RDF view on relational databases. It enables executing SPARQL queries on data in relational databases, mapped to RDF. The goal of D2RQ/Update is to enable executing SPARQL/Update statements, such as INSERT and DELETE, on the mapped data. It is a prototype extension to D2RQ platform that can be used for demonstrations and experimenting with Semantic Web technologies. It was tested only with MySQL and only on the example database and mapping that appear in the D2RQ Mapping Language .
The work is done as part of my M.Sc. studies at Department of Computer Science, Technion - Israel Institute of Technology, Haifa, Israel, under supervision of Dr. Yaron Kanza. The work on D2RQ/Update was largely influenced by the paper of M. Hert, G. Reif and H. C. Gall "Updating Relational Data via SPARQL/Update" .
D2RQ/Update uses the same mapping used by D2RQ, no additional information is required. The extension takes into account the database constraints, such as primary/foreign keys and non-nullable columns. D2RQ/Update uses constraints information from the database schema and tries to operate according to the constraints, in particular, to return meaningful errors in case of constraints violation. The algorithm, that describes the D2RQ/Update operation, is here.
Currently, the version of SPARQL/Update from 22 October 2009 is used (with MODIFY keyword).