Equality and Inequality in SPARQL

Sun, 13 Aug 2017 08:18:11 +0000

This brief blog post discusses issues surrounding expression semantics in SPARQL. Practices that people are used to from other languages (like the use of "=" and "!="), can often be confusing to new – and even not so new- SPARQL developers. The author suggests that an awareness of type errors will allow the user to understand what is occurring. Example queries show how type errors are treated when using FILTER. An alternative method involving project expressions or BIND is proposed.

URL: http://www.cray.com/blog/equality-inequality-sparql/
Keywords: SPARQL, BIND, FILTER, Type errors, Project expressions
Author: Vesse, Rob
Publisher: Cray
Date created: 2013-04-23 04:00:00.000
Language: http://id.loc.gov/vocabulary/iso639-2/eng
Time required: P10M
Educational use: instruction
Educational audience: student
Interactivity type: expositive

SPARQL Tutorial: Results

Abi Evans — Thu, 13 Aug 2015 03:26:18 +0000

This tutorial describes the four result forms used by SPARQL: SELECT, CONSTRUCT, DESCRIBE,and ASK. Also discusses the solution modifiers: PROJECTION, OFFSET/LIMIT, ORDER BY, and DISTINCT.

URL: http://jena.apache.org/tutorials/sparql_results.html
Keywords: SPARQL
Publisher: The Apache Software Foundation
Language: http://id.loc.gov/vocabulary/iso639-2/eng
Time required: P5M

Uses projection to transform a solution sequence into one involving only a subset of the variables. – Linked Data for Professional Education

Equality and Inequality in SPARQL

SPARQL Tutorial: Results