- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Thu, 18 Aug 2011 11:02:02 +0100
- To: public-lod@w3.org, Semantic Web <semantic-web@w3.org>
On 18/08/11 00:03, Danny Ayers wrote:
> Which aggregate functions are needed?
> ARQ has some support (very possibly more than) listed here:
> http://jena.sourceforge.net/ARQ/group-by.html
>
> [Andy, are there any more query examples around? I can't seem to get
> count(*) working here]
>
ARQ runs in standards mode (SPARQL 1.1) by default:
SELECT (count(*) AS ?C) { ?s ?p ?o }
Older style,
SELECT count(*) { ?s ?p ?o }
will work if you choose syntaxARQ (which is ticking "SPARQL extended
syntax" in the validator [1] or the same service in the Fuseki download.
ARQ supports all the SPARQl 1.1 aggregates [2]
COUNT, SUM, MIN, MAX, AVG, GROUP_CONCAT, and SAMPLE.
Let me know if you are stil having problems - the jena users list is
jena-users AT incubator.apache.org
Andy
[1]
http://www.sparql.org/query-validator.html
[2]
http://www.w3.org/TR/sparql11-query/#aggregates
Received on Thursday, 18 August 2011 10:02:44 UTC