Get Value from table by using relation in query build datasource in MSD axapta

 ReqTrans reqTrans;  
 ReqPo reqPo;  
 Query query;  
 QueryBuildDataSource qbds;  
 QueryBuildRange qbr;  
 QueryRun qr;  
 ;  
 query = new Query();  
 qbds = query.addDataSource(tablenum(ReqPO));  
 qbds.addDataSource(tablenum(ReqTrans)).relations(true);  
 qr = new QueryRun(query);  
 while(qr.next())  
 {  
 reqPo = qr.get(tablenum(ReqPO));  
 reqTrans = qr.get(tablenum(ReqTrans));  
 info(reqPo.RefId);  
 }