This slide tutorial focuses on using various operators in SPARQL queries. Several examples are provided which include the RDF data being queried, the SPARQL query itself, and the result table. This is followed by quiz questions which ask the user to query DBpedia's SPARQL endpoint. The answers to the question (in the form of completed SPARQL queries) are included.
URL: http://skkudatalab.weebly.com/sparql-operators.html
Keywords: DBpedia, SPARQL
Author: Oh, Sam
Publisher: Sungkyunkwan University (SKKU)
Date created: 2016-11-22 05:00:00.000
Language: http://id.loc.gov/vocabulary/iso639-2/eng
Time required: P40M
Educational use: instruction
Educational audience: professional
Interactivity type: expositive
- Accesses DBPedia's SNORQL/SPARQL endpoint and issues simple queries.
- Understands the use of datatypes and language tags with literals.
- Uses FILTER to formulates queries that eliminate solutions from a result set.
- Uses NOT EXISTS to limit whether a given graph pattern exists in the data.
- Uses OPTIONAL to formulate queries to return the values of optional variables when available.
- Uses UNION to formulate queries with multiple possible graph patterns.
- Uses ORDER BY to define ordering conditions by variable, function call, or expression.
- Uses the lang() function to return the language tag of an RDF literal.
- Uses the regular expression (regex()) function for string matching.