This brief tutorial emphasizes that RDF is semi-structured data, which means that SPARQL has the ability to query for data but will fail when that data does not exist. That is, unless one uses an optional part to extend the information found in a query solution but to return the non-optional information anyway. Also discusses using OPTIONALS with FILTERS, and using caution when using the same variable in two or more OPTIONALS clauses.

Keywords: SPARQL, BIND
Publisher: The Apache Software Foundation
Time required: P10M
Educational use: instruction
Educational audience: professional
Interactivity type: mixed

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