Set Standard Prefix Names for common vocabularies

In order to set standard prefix names for common vocabularies on dumps to either .n3 or .ttl, you should use the xml_set_ns_decl Virtuoso function.

The initial list of namespace declarations can be found by executing from iSQL or Conductor UI:

SQL> SELECT * FROM DB.DBA.SYS_XML_PERSISTENT_NS_DECL;

Example

1. Load the ontology, for ex.:
   

   
   SQL> DB.DBA.RDF_LOAD_RDFXML (http_get('http://lod.taxonconcept.org/ontology/txn.owl'), '', 'http://lod.taxonconcept.org/ontology/txn.owl#');
   
   Done. -- 109 msec.
   

   
   
2. Check total triples retrieved:
   

   
   SQL>SPARQL 
   SELECT COUNT(*)  
   from <http://lod.taxonconcept.org/ontology/txn.owl#>
   WHERE {?s ?p ?o};
   callret-0
   INTEGER
   _______________________________________________________________________________
   
   495
   
   1 Rows. -- 16 msec.
   

   
   
3. Register the XML NS prefix:
   

   
   SQL>DB.DBA.XML_SET_NS_DECL ('txn', 'http://lod.taxonconcept.org/ontology/txn.owl#', 2);
   Done. -- 0 msec.
   

   
   
4. Use the prefix, for ex. executing:
   

   
   SQL>SPARQL 
   SELECT COUNT(*) 
   WHERE
      {
        ?s ?p txn:SpeciesConcept
       };
   
   callret-0
   INTEGER
   _______________________________________________________________________________
   
   25
   
   1 Rows. -- 0 msec.