QuerySpec for DB query

import wt.change2.WTChangeOrder2;
import wt.change2.WTChangeOrder2Master;
import wt.fc.PersistenceHelper;
import wt.fc.QueryResult;
import wt.lifecycle.LifeCycleHistory;
import wt.lifecycle.ObjectHistory;
import wt.query.QueryException;
import wt.query.QuerySpec;
import wt.query.SearchCondition;
import wt.util.WTAttributeNameIfc;
import wt.util.WTException;

/**
 * $Rev:: $: Version
 * $Author:: $: Dernier modificateur
 * $Date:: $: Date du dernier commit
 * Url de la version la plus recente
 * $HeadURL$
 **/
public class MyQuery {

 public static void main(String[] args) {
 /*
 select * from wind.WTChangeOrder2 ch left outer join wind.WTChangeOrder2Master chm
 on ch.idA3masterReference = chm.idA2A2
 left outer join wind.ObjectHistory obj on obj.idA3A5 = ch.idA2A2
 left outer join wind.LifeCycleHistory lch on lch.idA2A2=obj.idA3B5
 where chm.WTCHGORDERNUMBER = '00039'
 and lch.action='Set_State';
 */

 try {
 QuerySpec querySpec = new QuerySpec();
 int indChOrder = querySpec.appendClassList(WTChangeOrder2.class,true);
 int indChOrderMaster = querySpec.appendClassList(WTChangeOrder2Master.class,true);
 int indObjHistory = querySpec.appendClassList(ObjectHistory.class,false);
 int indLcHistory = querySpec.appendClassList(LifeCycleHistory.class,false);

 // Joins
 querySpec.appendWhere(new SearchCondition(WTChangeOrder2.class, "masterReference.key.id",WTChangeOrder2Master.class, WTAttributeNameIfc.ID_NAME),new int[]{indChOrderMaster,indChOrder});
 querySpec.appendAnd();
 querySpec.appendWhere(new SearchCondition(ObjectHistory.class, "roleAObjectRef.key.id",WTChangeOrder2.class, WTAttributeNameIfc.ID_NAME),new int[]{indObjHistory,indChOrder});
 querySpec.appendAnd();
 querySpec.appendWhere(new SearchCondition(LifeCycleHistory.class, WTAttributeNameIfc.ID_NAME,ObjectHistory.class, "roleBObjectRef.key.id"),new int[]{indLcHistory,indObjHistory});

 // Select

 querySpec.appendAnd();
 querySpec.appendWhere(new SearchCondition(WTChangeOrder2Master.class, WTChangeOrder2Master.NUMBER, SearchCondition.EQUAL, "00039"),new int[]{indChOrderMaster});
 querySpec.appendAnd();
 querySpec.appendWhere(new SearchCondition(LifeCycleHistory.class, LifeCycleHistory.ACTION, SearchCondition.EQUAL, "Set_State"),new int[]{indChOrderMaster});

 QueryResult queryResult = PersistenceHelper.manager.find(querySpec);
 
 // use queryResult ...
 

 } catch (QueryException e) {
 e.printStackTrace();
 } catch (WTException e) {
 e.printStackTrace();
 }

 }

}