%META:TOPICPARENT{name="VirtTipsAndTricksGuide"}%

---+How can I use CONSTRUCT with Prepared Statements?
Assume a given query which uses pragma <b><nowiki>output:format '_JAVA_'</nowiki></b> with CONSTRUCT: 

<verbatim>
SPARQL DEFINE output:format '_JAVA_'
   CONSTRUCT { ?s ?p ?o }
WHERE
  { 
    ?s ?p ?o . 
    FILTER (?s = iri(?::0)) 
  }
LIMIT 1
</verbatim>

In order to work correctly, the query should be modified to:

<verbatim>
SPARQL DEFINE output:format '_JAVA_'
   CONSTRUCT { `iri(?::0)` ?p ?o }
WHERE
  { 
    `iri(?::0)` ?p ?o 
  }
LIMIT 1
</verbatim>

Equivalent variant of the query is also:

<verbatim>
SPARQL DEFINE output:format '_JAVA_'
  CONSTRUCT { ?s ?p ?o }
WHERE
  { 
    ?s ?p ?o . 
    FILTER (?s = iri(?::0)) 
  }
LIMIT 1
</verbatim>

---+++Related
   
   * [[VirtTipsAndTricksGuide][Virtuoso Tips and Tricks Collection]]
   * [[http://docs.openlinksw.com/virtuoso/rdfandsparql.html][RDF Data Access and Data Management]]