title: how to combine two columns in sparql?
body: <p>Hi I have the output of results like this :</p>
  
  <pre><code>?name ?o ?x
  ------------
  ABCD  xyz ghh
  PQR   xyz hij
  </code></pre>
  
  <p>how do I combine the columns ?o and ?x into one column called papers?
  I need the output to be like this :</p>
  
  <pre><code>?name ?papers
  --------------
  ABCD  (xyz, ghh, hij)
  </code></pre>
  
  <p>Note that PQR and ABCD are replaced only by ABCD. ABCD and PQR have the same property called mbox_sha1sum</p>
  
  <p>The above two were examples. I need them to be like so:</p>
  
  <p>This is the current sparql query :</p>
  
  <pre><code>PREFIX xmlns: &lt;http://xmlns.com/foaf/0.1/&gt; 
  PREFIX ontoware: &lt;http://swrc.ontoware.org/ontology#&gt;
  SELECT DISTINCT ?name ?x ?o
  WHERE { 
   ?s xmlns:mbox_sha1sum ?hash.
   ?s xmlns:made ?o.
   ?s xmlns:name ?name.
   ?o ontoware:year "2009".
   ?r xmlns:mbox_sha1sum ?hash.
   ?r xmlns:made ?x.
   ?x ontoware:year "2008".
  }
  </code></pre>
  
  <p>I need to basically combine ?o and ?x into one column called ?papers
  If it helps, ?s and ?r have different IRI</p>