Example11.java: SPARQL query with SELECT Cast

This example "converts" two Fahrenheit temperatures (18.1 and 32.0) to Celsius temperatures.

import com.hp.hpl.jena.update.*;
import com.hp.hpl.jena.query.*;
import com.hp.hpl.jena.rdf.model.Model;
import oracle.rdf.kv.client.jena.*;

public class Example11 
{
  
  public static void main(String[] args) throws Exception
  {

String szStoreName  = args[0];
String szHostName   = args[1];
String szHostPort   = args[2];
String szModelName  = args[3];
    
// Create Oracle NoSQL connection 
OracleNoSqlConnection conn 
           = OracleNoSqlConnection.createInstance(szStoreName,
                                                  szHostName, 
                                                  szHostPort);
    
// Create model from named graph
Model model = 
      OracleModelNoSql.createOracleModelNoSql(szModelName, conn);
    
// Clear model
model.removeAll();
  
    
String insertString =
" PREFIX xsd: <http://www.w3.org/2001/XMLSchema#> "           +
" INSERT DATA "                                               +
" { "                                                         +
"     <u:Object1> <u:temp> \"18.1\"^^xsd:float ; "            +
"     <u:name> \"Foo... \" . "                                +
"     <u:Object2> <u:temp> \"32.0\"^^xsd:float ; "            +
"     <u:name> \"Bar... \" . "                                +
" } ";
    
    
System.out.println("Execute insert action " + insertString);
UpdateAction.parseExecute(insertString, model);
    
String szQuery =
" PREFIX fn: <http://www.w3.org/2005/xpath-functions#> "         +
" SELECT ?subject ?temp ((?temp - 32.0)*5/9 as ?celsius_temp) "   +
" WHERE { ?subject <u:temp> ?temp } ";
    
System.out.println("Execute query " + szQuery);
    
Query query = QueryFactory.create(szQuery, Syntax.syntaxARQ);
QueryExecution qexec = QueryExecutionFactory.create(query, model);
    
try {
      ResultSet results = qexec.execSelect();
      ResultSetFormatter.out(System.out, results, query);
    }
    
finally {
      qexec.close();
    }
    
model.close();
conn.dispose();    
  }
}

The following are the commands to compile and run this example, as well as the expected output of the java command.

javac -classpath ./:./jena-core-2.7.4.jar:./jena-arq-2.9.4.jar: \
./sdordfnosqlclient.jar:./kvclient.jar:./xercesImpl-2.10.0.jar: \
./slf4j-api-1.6.4.jar:./slf4j-log4j12-1.6.4.jar:./log4j/1.2.16.jar: \
./jena-iri-0.9.4.jar:./xml-apis-1.4.01.jar Example11.java

javac -classpath ./:./jena-core-2.7.4.jar:./jena-arq-2.9.4.jar: \
./sdordfnosqlclient.jar:./kvclient.jar:./xercesImpl-2.10.0.jar: \
./slf4j-api-1.6.4.jar:./slf4j-log4j12-1.6.4.jar:./log4j/1.2.16.jar: \
./jena-iri-0.9.4.jar:./xml-apis-1.4.01.jar Example11 <store_name> \
<host_name> <host_port> <graph_name>

Execute insert action  PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>  
INSERT DATA  {  
<u:Object1> <u:temp> "18.1"^^xsd:float ; <u:name> "Foo... " .
<u:Object2> <u:temp> "32.0"^^xsd:float ; <u:name> "Bar... " . }

Execute query  PREFIX fn: <http://www.w3.org/2005/xpath-functions#>
SELECT ?subject ?temp ((?temp - 32.0)*5/9 as ?celsius_temp)  
WHERE { ?subject <u:temp> ?temp }
----------------------------------------------------
| subject     | temp | celsius_temp                |
====================================================
| <u:Object1> | 18.1 | -7.722222222222222222222223 |
| <u:Object2> | 32   | 0.                          |
----------------------------------------------------