- From: Leigh Dodds <leigh.dodds@talis.com>
- Date: Fri, 6 Mar 2009 10:15:27 +0000
- To: public-rdf-dawg-comments@w3.org
Hi, I have the following featur esuggestion for the WG. Feature: Parameterised Queries Feature Description: Extend the SPARQL protocol such that additional URL parameters in the query string (or a subset that match a specific naming convention) are reflected into the query as initial variable bindings. Example: E.g. for a query such as: PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT ?name WHERE { ?x foaf:name ?name. ?x foaf:weblog ?blog. } A protocol request of the form: /sparql?query=...&blog=http://www.example.org/blog Would bind ?blog to the value in the URL parameter before it is matched against the dataset. Existing Implementations ARQ supports this usage in its core URL, and I have used this to implement the above style of parameter passing in several apps and endpoints whilst at my previous employer. Use Cases Enable support SQL style parameterised query directly from the SPARQL protocol. In conjunction with the proposed Query By Reference feature it enables the creation of simple "web APIs" using only the SPARQL protocol. E.g. I am able to publish a common SPARQL query that does some useful data extraction, and then reuse that query by altering the passed parameters. Even without the Query By Reference feature it would simplify interaction with an endpoint (change url parameter(s) not query) and would allow the endpoint to cache and parse a query for repeated use, thereby removing any query parsing overheads. Cheers, L. -- Leigh Dodds Programme Manager, Talis Platform Talis leigh.dodds@talis.com http://www.talis.com
Received on Friday, 6 March 2009 10:16:07 UTC