Created on Feb. 23, 2013, 9:09 a.m. by Hevok & updated by Hevok on May 2, 2013, 5:19 p.m.

First of all in SPARQL one has to define SPARQL Variables, which means one want to access a Data Knowledge Base/Database one need to prepare Variables that cover the Facts, the Things, the Resources one get out of the Knowledge Base. In SPARQL one simple differentiates/distinguishes between Variables and other Resources in the way that one puts a Question Mark in front of the Name of the Variables one is using. In the same why as in SQL for Databases, a Query is performed with a SELECT Statement. For example one can select three Variables (?title, ?author and ?published) and if one is preparing a selection Statement like this the answer will be given as some Table. The Table of course will have columns and within the Columns one will find again Columns labeled by the Variables as by the SELECT Statement.

  • SPARQL Variables are bound to RDF terms
    • ?journal, ?aging, ?cure
  • In the same way as in SQL a Query for variables is performed via SELECT Statement
    • e.g. SELECT ?title ?author ?published
  • A SELECT Statement returns Query Results as a Table

    ?title ?author ?published 1985 Cabal 1984 New Terra EVA 2015 Nothing Hevok 2013

Overall one makes a SELECT Statement which means one Queries for some Variables at some SPARQL Endpoint and the result would be a Table that is organized according the Variables one is queering within the SELECT Statement.


Tags: query, keyword, database
Categories: Tutorial
Parent: SPARQL

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