[Virtuoso-users] Subquery and SAMPLE keyword (SPARQL 1.1)

[Houda kr]

Hi,

I need  to know how to return one random label (for each item) when the item
has several labels (using SPARQL). I tried the following query, but it
returns the same label for all persons

SELECT ?person ?name  WHERE {
?person a foaf:Agent .
{ SELECT ?name WHERE {
    ?person rdfs:label ?name
} LIMIT 1 } .
}

Same behavior on DBpedia SPARQL endpoint (see
http://answers.semanticweb.com/questions/2726/using-sample-keyword-and-subqueries-at-dbpediaorg).
I need to understand why this query doesn't work since the second query
should retrieve the first name for each resource from the first query.

I am trying to use the SAMPLE keyword (SPARQL 1.1), but it is not supported
by the current version of Virtuoso. I want to know when the SPARQL 1.1 will
be fully integrated in the open source distribution. Any other suggestion is
welcome.


thanks in advance
Houda