title: Sparql Select only one label and comment of classes
body: <p>I am trying to select one label and comment of classes but group by doesn't work as expected. The following query is an example of the select.</p>
  
  <pre><code>SELECT ?class ?label ?comment WHERE
  {
  
    {SELECT DISTINCT ?class WHERE { {?uri rdf:type ?class}UNION {?class rdf:type owl:Class} UNION {?class rdf:type rdfs:Class} }OFFSET 0 LIMIT 100}
  
  .optional{?class rdfs:label ?label}
  
  .optional{?class rdfs:comment ?comment}
  
  }GROUP BY ?class
  </code></pre>
  
  <p>The goal is to to have every class uri with one label and comment
  But am getting results as : </p>
  
  <pre><code>http://dbpedia.org/ontology/Activity    "attività"@it   
  http://dbpedia.org/ontology/Activity    "活動"@ja
  </code></pre>
  
  <p>Any idea ?</p>