Dave Beckett's blog

SPARQL RDF Query Language Reference update v1.7

2005-07-26 14:58

I've updated my SPARQL RDF Query Language Reference to match the recently released SPARQL Query Language 21 July 2005 Working Draft.

While doing that I have also got a list of some of the more visible (syntax) changes, which is are as follows (this may not be a complete list):

  • Blank nodes are allowed in any part of a triple pattern and act as variables that cannot be SELECTed, that is, cannot be returned in variable bindings results.
  • FILTER expressions now normally take ()s except where it isn't ambiguous, such as when any of the builtin functions such as REGEX are used at the root of the expression e.g. FILTER REGEX(...)

  • The FROM URI keyword is now repeatable which adds more triples to the background graph, doing an RDF merge. Any boundaries between loaded graphs are lost. If you want those, use FROM NAMED.
  • ASC and DESC in ORDER BY now use ()s not []s.
  • ORDER BY can now explicitly take expressions and extension functions without the need for ASC (default) or DESC.
  • The arguments of REGEX are now expressions not constant literals
  • The pattern syntax of REGEX is from XQuery 1.0 / XPath 2.0 Functions and Operators modifying it from XML Schema Datatypes Regular Expressions and similar to a Perl subset.

ObPlug: You can try most of this out in my Rasqal RDF query demo which is updated for the syntax, but the engine doesn't do all the language yet.