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.