Tag Archives: triples

SPARQL 101: how to get started with the linked data search query language

How do you get started with SPARQL, the language for querying linked data? An Open Data Camp 7 session, led by Jen, aimed to help newbies get going.

Liveblogging: prone to error, inaccuracy, and howling crimes against grammar and syntax. Post will be updated in the coming days.

Learning about SPARQL and linked data

More and more open data platforms are either becoming linked data at their core, or they have offshoots that add it. The data underneath linked data is RDF – and SPARQL is the query language for RDF. Most SparQL endpoint look like a query box with gobbledegook with them – where you are expected to write your own gobbledegook. It’s somewhat intimidating,

In most cases, they also provide an API so you can programmatically query the information – but somebody needs to develop that. SPARQL endpoints give you direct access to all the data. The structure of RDF — the triples — creates a very standardised data format that you can query for whatever you like.

There’s a SPARQL playground where you can experiment with queries. There’s more than one of them, in fact.

You can use the query interface to hone down on the data you want, and then download it as a CSV, or use that as a query to use programatically. The playgrounds help you figure out how to construct queries by showing you the results on a sample dataset.

Continue reading SPARQL 101: how to get started with the linked data search query language

Handy tools for Open Data users

Warning: Liveblogging – prone to error, inaccuracy, and howling affronts to grammar. This post will be improved over the course of a few days.

 

A session sharing handy open data tools that participants have built or found that might just make your life easier.

Google document for this session

Chris Gutteridge, University of Southampton

  • Prefix.cc – look up namespaces for RDF
  • Graphite PHP Linked Data Library – most of the RDF tools are written by academics who are clever, and assume that others are clever. Chris just wanted to build something easy – and that’s what Graphite is. It’s an easy way of exploring linked data. It makes it easy to debug the RDF code you create. The development version has a SPARQL interface, making it easy to build SPARQL queries.
  • Alicorn – a tool for generating pages from linked data.
  • RDF Browser – a quick and dirty RDF browser
  • Triple Checker – a tool to check for common errors in RDF Triples.
  • NTCat
  • Hedgehog – an RDF publishing platform

All of the source code for these is available on GitHub.

James Smith, ODI

The ODI tends to focus on simpler tools – and formats like CSV. Some much data out there is in poor condition.

  • CSVlint – a validator for data in CSV format, which also works with schemas. In alpha currently, and aiming for beta this year.
  • Open Data Certificates – a project to help people make assurances around their data, that gives others the confidence to build from it.
  • Git Data Publisher – a tool to help you publish your open data, guiding you through what you need to do.

Others

  • Gangplank – an open source data publishing platform