title: DBPedia Sparql Endpoint: keyword OPTIONAL
body: <p>I'm trying to run the following SPARQL query: </p>
  
  <pre class="lang-sql prettyprint-override"><code>SELECT ?band, ?genre
  WHERE
  {
        ?band a umbel-rc:Band_MusicGroup.
        OPTIONAL{?band dbo:genre ?genre}.
  }
  </code></pre>
  
  <p>but in the result there are no bands for which a <code>dbo:genre</code> is not defined (such as Coldplay <a href="http://dbpedia.org/page/Coldplay" rel="nofollow noreferrer">look here</a>).
  Optional does not work in DBpedia?</p>