D2RQ is an awesome tool for anyone who wants to see his Relational Database as a RDF based system. Its easy to use and works with most of the Databases available. It also supports SPARQL and has a query interface by default.

1. D2RQ
ACCESS RDB AS VIRTUAL RDF
(LAGECY DATA MEETS THE GLOBAL DATASETS)

2. What can it Do ?
• Access RDB as RDF read only graphs.
• Access RDB without "REPLICATION" into Triplestore as RDF.
• Make your content available as RDF and exploit it with Linked Data
Methodologies.
• Its Open Source, having Apache License, Version 2.0
• Supports various DB vendors.

3. Features
• Query Non-RDF database using SPARQL
• Access the Content of non-RDF databases as Linked Data over the web.
This makes legacy data make sense.
• Helps in dumps creations in order to load data into the Triple stores.
• Helps in accessing Non-RDF databases or RDB using Apache-Jena.
• Provides an AJAX based Query Browser for Querying RDB using SPARQL.

4. Architecture
Taken from D2RQ website

5. What this Platform has for me/us?
• A mapping language which connects the RDB database with the existing set
of ontologies
• D2RQ Engine that integrates seamlessly with Apache Jena to process
SPARQL upon the RDB.
• D2RQ server which acts as a port for viewing Linked Data over the web.
• It also Provides SPARQL endpoint with AJAX enabled endpoint.

6. How does the mapping happen ?
• D2RQ has a Mapping Language that does direct mapping of the RDB to
RDF.
• D2RQ Provides a tool to generate a custom mapping for the above purpose.
• Mappings treat Database Tables as Classes and the Column name as the
Properties to the Classes.
• D2RQ also provides a bridge to map the individual to the Domain
Knowledge i.e Ontologies.

7. Features of D2RQ Server
• Gives you Browsable content in RDF format (Human Readable), through which
one can navigate
• Resolvable URI's
• Content Negotiation
• SPARQL endpoint explorer, Supports SPARQL1.1. Queries over SPARQL Protocol
• Can be configured to serve files stored in Databases CLOB/BLOB
• Serving Vocabulary
• Publishing Meta Data

8. Basic Architecture of how D2RQ fits in with
RDB

9. Databases Supported By D2RQ
• Oracle
• MySQL (Drivers are provided by D2RQ)
• PostgreSQL (Drivers are provided by D2RQ)
• SQL Server
• HSQLDB
• Interbase/Firebird
• ODBC Datasources (With help of ODBC-JDBC Bridge but has limitations)

10. Getting Started
• Download D2RQ
• Generate the Mapping file against a compatible Database
• There is a tool included that would generate mapping after throughly inspecting
your database
• Modify the mapping file if required
• Run the D2RQ server along with the Mapping file
• Thats DONE!!!
• Now SPARQL your RDB and get the results of your choice

11. Important Links
• D2RQ : http://d2rq.org/
• D2RQ Dowload : https://github.com/downloads/d2rq/d2rq/d2rq-0.8.1.zip
• D2RQ Mapping : http://d2rq.org/generate-mapping
• D2RQ Server : http://d2rq.org/d2r-server
• D2RQ Query : http://d2rq.org/d2r-query
• dump-rdf : http://d2rq.org/dump-rdf
• D2RQ + JenaAPI : http://d2rq.org/jena

12. Contact me
• LinkedIn : in.linkedin.com/in/shivkumargnesh
• Twitter : @shivkumarganesh
• Gmail : gshiv.sk@gmail.com
• Hotmail : shivkumar_srm@hotmail.com
• Skype : gshiv.sk

13. Thanks