Thanks Damian. That did the trick!
On 10/05/2011 11:39 AM, Damian Steer wrote:
On 5 Oct 2011, at 18:40, Eric Scott wrote:
Hi all-
Hi Eric,
I've tried using a subquery like this:
SELECT ?entity ?arbitraryLabel
where
{
?entity my:hasFeature my:VeryImportantFeature.
{
SELECT ?arbitraryLabel
{
?entity my:hasLabelSet ?labelSet.
?labelSet my:hasLabel ?arbitraryLabel.
}
LIMIT 1
}
}
on the assumption that the variables in the main query are scoped in such a way
that they are shared with the subquery.
What's happening is this: sparql is evaluated from inside out. So your inner
select happens first, and you get one row:
?arbitraryLabel = "unrelated label 25"
which is then (cross) joined with the result of ?entity my:hasFeature
my:VeryImportantFeature.
You could make the inner select:
{
SELECT ?entity ?arbitraryLabel
...
}
which gives a more understandable result, perhaps, in that you'll get the
entity with that label returned.
One way to get what you want is:
SELECT ?entity (SAMPLE(?label) AS ?arbitraryLabel)
where
{
?entity my:hasLabelSet ?labelSet .
?labelSet my:hasLabel ?label .
}
GROUP BY ?entity
which says: I want one entity per row. Pick any label.
Damian
