résultat vide d'une requete MDX :(

Bonjour,
Je veux développer une application OLAP. Quand j'ai testé des requetes MDX, certaines requetes ne donnent aucun résultat.
Dans mon programme ci-dessous, les requetes q1, q3, q4 s'exécutent et donnent un résultat vide :(


//debut du programme OLAP
import mondrian.olap.*;
import java.io.PrintWriter;

public class Main {

public static void main(String[] args) {
try{
Class.forName("mondrian.olap4j.MondrianOlap4jDriver");
String urlJdbc="Provider=mondrian;"+ "Jdbc=jdbc:oracle:thin:foodmart/foodmart@192.168.1.2:1521:dbxx;"+"Catalog=C:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\webapps\\mondrian\\WEB-INF\\queries\\FoodMart.xml;"+ "JdbcDrivers=oracle.jdbc.OracleDriver";
Connection connection= DriverManager.getConnection(urlJdbc,null);
String mdx1 = "select { [Measures].[Store Sales], [Measures].[Unit Sales] } on columns,\n" + "{[Product].[Product Family].[Drink].children} on rows \n" + "from Sales where ([Time].[1997]) ";
String mdx2 = "select { [Measures].[Store Sales], [Measures].[Unit Sales] } on columns,\n" + "{[Product].members} on rows \n" + "from Sales where ([Time].[1997]) ";
String mdx3 = "select {[Measures].[Store Sales]} on columns,\n" + "FILTER({CrossJoin({[Product].members }, {[Time].[1997]})}, [Measures].[Unit Sales]> 6000) on rows \n" + "from Sales ";
String mdx4 = "select {[Measures].[Store Sales]} on columns,\n" + " DESCENDANTS([Store].[Store Country].[USA], 4) on rows \n" + "from Sales ";

Query q1 =connection.parseQuery(mdx1);
Query q2 =connection.parseQuery(mdx2);
Result res1=connection.execute(q1);
Result res2=connection.execute(q2);
res1.print(new PrintWriter(System.out));
res2.print(new PrintWriter(System.out));
Query q3 =connection.parseQuery(mdx3);
Query q4 =connection.parseQuery(mdx4);
Result res3=connection.execute(q3);
Result res4=connection.execute(q4);
res3.print(new PrintWriter(System.out));
res4.print(new PrintWriter(System.out));
}catch(Exception e){
System.out.print(e.toString());
}
}
}
// Fin du programme OLAP

S'il vous plait, aidez moi à trouver une solution pour que ce type de requête donne un résultat non vide.
Merci.