Can't execute a specific SPARQL query on DBPedia :/ - sparql

Question

On this site, for example, take the first SPARQL query and make something very similar:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX p: <http://dbpedia.org/property/>
SELECT *
WHERE {
?name p:name <http://dbpedia.org/resource/Olivier_Theyskens> .
}
Try to execute it: here
And I get no results. However, modify the query to the following:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX p: <http://dbpedia.org/property/>
SELECT *
WHERE {
?name p:name ?otherthing.
}
And I get results, even though they're not the results I want.
Why doesn't the first query work -- what am I doing wrong? :/

Answer 1

In this case, I think it's because you're ordering your query statement backwards.
The DBpedia resource (<http://dbpedia.org/resource/Olivier_Theyskens>) is the Entity or Subject (?s), the property (p:name) is the Attribute or Predicate (?p), and the value of that property (?name) is the Value or Object (?o).
SPARQL expects all statements to be { ?s ?p ?o }, but yours seems to be written as { ?o ?p ?s }...
To sum up, if you try this query --
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX p: <http://dbpedia.org/property/>
SELECT *
WHERE
{
<http://dbpedia.org/resource/Olivier_Theyskens> p:name ?name .
}
-- you'll get the results I think you want.

Answer 2

The problem with your first query is that p:name links to Literal and you try to match a URI.
If you want your first query to work you have to to use the property http://dbpedia.org/ontology/artist that links to the URI and not the literal:
SELECT *
WHERE {
?s <http://dbpedia.org/ontology/artist> <http://dbpedia.org/resource/The_Velvet_Underground> .
}
Notice the different name space for the property <http://dbpedia.org/ontology/artist> this namespace contains ontology instead of property - ontology is the one used for object properties.