HQL join query not executing

[saravanan sambandam]

I have 3 tables

user_master : contain with user_id, user_name
group_master : contain with group_id, group_name
user_group : contain with user_group_id, group_id, user_id

SQL statment : select a.user_group_id, b.group_id, b.group_name from user_group a left outer join group_master b on b.group_id=a.group_id;
but when i am using HQL is not execute what i did the mistake? please let me know

 
public class GroupMasterPojo {
private int id;
private String name;

getter && setter

-------

public class UserGroupPojo {

private int id;   //user_group_id
private int gid; // group_id
private int uid; // user_id

getter && setter

[b][color=blue] String hql_query = "FROM GroupMasterPojo AS grp INNER JOIN grp.UserGroupPojo  AS usrGrop"; [/color][/b]

try {
               this.hibSessionObj 	= getCurrentSessionObj();
	trans 		= this.hibSessionObj.beginTransaction();
	Query query 	= hibSessionObj.createQuery(hql_query);
	List <UserGroupPojo> usrGrpList = query.list();
	Iterator uGrpItr = usrGrpList.iterator();
	UserGroupPojo usrGrpPojo  = new UserGroupPojo();
	while(uGrpItr.hasNext()){				
	usrGrpPojo = (UserGroupPojo)uGrpItr.next();
	usrGrpArList.add(usrGrpPojo);
	System.out.println("user Group Id - " + usrGrpPojo.getId());
	System.out.println(" Group Id - " + usrGrpPojo.getGid());
	System.out.println(" User Id - " + usrGrpPojo.getUid());
	//System.out.println(" group name - " + usrGrpPojo.getGroupName());			
	}
	trans.commit();
	} catch (HibernateException e) {
		trans.rollback();
	                System.err.println(AEFormInterface.ERROR_QUERY + " - " 	+ localMethod + " - " + e.getStackTrace());
	} finally {
		this.hibSessionObj.flush();
		this.hibSessionObj.close();
	}

This query is not executing please help me where i did the mistake.
Thanks
Saran.