Query RDF with SPARQL

Question

I’m looking for a hassle-free way to query RDF with SPARQL.

It would be great if it’s possible to paste the RDF into a textarea (instead of having to select a file). At best it would support all these ways how to specify the RDF to be queried:

• paste the RDF
• select a local RDF file
• enter a URL to an online RDF file
• load the RDF as specified in the SPARQL query (via FROM, or whatever mechanisms SPARQL supports)

The more RDF serializations formats are supported, the better. It should at least support Turtle (but I don’t require this, as I could use a converter if a recommended solution is worth it).

I don’t have any restrictions regarding the result format.

A solution must

• be FLOSS,
• run natively on GNU/Linux, and
• work offline.

Answer 1

I recommend RDF4J Server, in combination with RDF4J Workbench (disclosure: I am on the RDF4J development team). Eclipse RDF4J was formerly known as OpenRDF Sesame.

Your must criteria:

• RDF4J is FLOSS (EDL - Eclipse Distribution License)
• RDF4J runs on GNU/Linux and any other OS (Java)
• RDF4J Server and Workbench work offline (they are webapps, but no internet is needed to contact localhost)

RDF4J Server is RDF4J's Database Server application, which manages the triplestores and offers access via the RDF4J APIs and via SPARQL.

RDF4J Workbench is a client application that offers many useful functions:

• RDF upload functionality, supporting copy paste in a textarea, upload of a local file, and upload from a URL.
• supports import and export of all common RDF syntax formats, including Turtle.
• a full SPARQL query editor, with syntax hightlight, autocomplete, and saved queries.
• repository explorer functionality.
• SPARQL 1.1 Update functionality allowing you to add/modify/delete RDF via SPARQL.

To install, follow these steps:

1. Install Apache Tomcat on your local machine
2. Download the RDF4J SDK distribution and locate the two war files in it (uncompress and you'll find them in the war/ directory)
3. Deploy the two war files, rdf4j-server.war and rdf4j-workbench.war, to your local Tomcat installation.
4. Visit http://localhost:8080/rdf4j-workbench to enter the RDF4 Workbench.