Hi<br><br>After installing Redland I wanted to check it's integration with Open Source Virtuoso.<br><br>I've configured the ODBC connection and run utils/redland-virtuoso-test but the last 3 tests failed.<br>After inspecting the source code I found that the problem was in the query declaration<br>
<br>query=librdf_new_query(world, (char *)"vsparql", NULL, (const unsigned char *)query_cmd, NULL);<br><br>By replacing these lines by the following I was able to successfully run tests 19, 20, 21<br><br>query=librdf_new_query(world, "vsparql", NULL, (const unsigned char *)query_cmd, NULL);<br>
<br>In particular I want to perform SPARQL GROUP BY queries over Virtuoso, so I decided to modify the tests in order to run this query:<br><br>SELECT ?s (sum(?o) AS ?sumO) <br>WHERE {graph <<a href="http://red">http://red</a>> { ?s ?p ?o }} <br>
GROUP BY ?s<br><br>Consider a graph <<a href="http://red">http://red</a>> that only contains the following triples (otherwise the sum operator can not be applied since ?o may bind to some non numeric values):<br><br>
rc |= add_triple_typed(world, context_node, model, "oo", "pp", "10^^<<a href="http://www.w3.org/2001/XMLSchema#int">http://www.w3.org/2001/XMLSchema#int</a>>");<br> rc |= add_triple_typed(world, context_node, model, "oo", "pp", "12^^<<a href="http://www.w3.org/2001/XMLSchema#int">http://www.w3.org/2001/XMLSchema#int</a>>");<br>
rc |= add_triple_typed(world, context_node, model, "oo", "pp", "15^^<<a href="http://www.w3.org/2001/XMLSchema#int">http://www.w3.org/2001/XMLSchema#int</a>>");<br><br>Surprisingly the query still raises an error, since VIrtuoso can not parse this object values as integers.<br>
<br>My workaround was to re define the add_triple_typed function, and now I actually pass type URLs as parameters, using <i>librdf_new_node_from_typed_literal</i> instead of <i>librdf_new_node_from_uri_string</i> to create the nodes.<br>
<br><br>I just wanted to know if this is ok or am I missing something?<br><br>Regards<br>Lorena<br><br><br><br><br><br><br><br clear="all"><br>-- <br>Lorena Etcheverry<br>