D2RQ
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D2RQ is an open source tool that allows accessing relational databases as virtual RDF graphs without replicating the data into a triplestore. It provides a mapping language to connect databases to ontologies and integrates with Apache Jena to process SPARQL queries over the databases. D2RQ also includes a server that publishes the database contents as browsable linked data through resolvable URIs and SPARQL endpoints.
D2RQ
- 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