Lab: Ontop

Topics

• Creating SQLite3 databases
• Creating OBDA or R2RML mappings
• Setting up Ontop in GraphDB
• Querying SQLite3 databases through a virtual Ontop KG

Useful materials

• SQLite3 installation and quick start
• GraphDB Ontop introduction and installation
• OBDA and R2RML mapping examples
• Federated SPARQL queries

Tasks

We recommend you run this exercise through the Ontop plugin to the free desktop version of OntoText's GraphDB tool. You can also use one of the open-source versions of Ontop.

Installing and running SQLite3

Task: Download and install a relational database system on your computer. We recommend the very light-weight and easy-to-install SQLite3.

Task: Create a folder on your local computer for this exercise. Go to the new folder and open a Console or Terminal window. Start SQLite3 with the name of a new database, for example 'MyTestDB.sqlite'.

Task: Based on the example files XXX XXX in XXX, create the following two tables and fill them with test data:

You can either enter SQL statements interactively one by one, or you can save them to a file and use SQLite3's .read command. Use the .exit command when you are done.