Filter by datatype
<p>I'm trying to filter by datatype in DBpedia. For example:</p>

<pre><code>SELECT *
WHERE {?s ?p ?o .
    FILTER ( datatype(?o) = xsd:integer) 
    } 
LIMIT 10
</code></pre>

<p>But I get no results, while there are certainly integer values. I get the same  from other endpoints using Virtuoso, but I do get results from alternative endpoints. What could be the problem? If Virtuoso does not implement this SPARQL function properly, what to use instead?</p>