This links to the PDF version of Ethan Gruber's webinar, which provides an introduction to SPARQL, a query language for RDF. Users will gain hands-on experience crafting queries, starting simply, but evolving in complexity. These queries will focus on coinage data at the SPARQL endpoint hosted by http://nomisma.org with numismatic concepts defined in a SKOS-based thesaurus and physical specimens from three major museum collections linked to these concepts. Results generated from these queries in the form of CSV may be imported directly into Google Fusion Tables for immediate visualization in the form of charts and maps.
Keywords: Geographic queries, SPARQL, Map geolocations
Author: Gruber, Ethan
Date created: 2014-08-01 07:00:00.000
Time required: P60M
Interactivity type: mixed
- Understands how to combine and filter graph patterns using operators such as UNION, OPTIONAL, FILTER, and MINUS.
- Understands that a SPARQL query matches an RDF graph against a pattern of triples with fixed and variable values.
- Understands the basic syntax of a SPARQL query.
- Uses aggregates to apply expressions over groups of solutions (GROUP BY, COUNT, SUM, AVG, MIN) for partitioning results, evaluating projections, and filtering.
- Uses the langMatches() function to match a language tag against a language range.
- Uses the regular expression (regex()) function for string matching.
- Uses DISTINCT to ensure solutions in the sequence are unique.
- Uses LIMIT to restrict the number of solutions processed for query results.
- Uses publicly available tools to visualize data.