学步园

需要以下文件：

Customer.java                            PO对象
Charge.java                                PO对象
TotalCharge.java                        用于保存统计结果Bean即是多表查询结果的所需字段
Customer.hbm.xml                      PO映射
Charge.hbm.xml                          PO映射
TotalChargeDao.java                  统计Dao定义
TotalChargeDaoImpl.java           统计Dao定义实现
DaoFactory.java                         Dao工厂
HibernateSessionFactory.java     Session工厂 

//下面是一个 TotalChargeDaoImpl.java 里实现多表查询的方法

public List statTotalCharge(Date statTimeBegin, Date statTimeEnd) throws DaoException{
        List res = new Vector();//将用于存放保存的结果集合
        Session session = null;
        ScrollableResults srs ＝ null;
        try{
            session = HibernateSessionFactory.openSession();//得到一个Hibernate Session
            //下面创建一个匿名Query实例并调用它的scroll()方法返回以ScrollableResults形式组织的查询结果
            srs = session.createQuery(“select b.name, count(a.fee) mix(a.chargeBeginTime) max(a.chargeEndTime) from charge a, customer b where a.idCustomer = b.idCustomer and a.chargeBeginTime >= ? and a.chargeEndTime < ? gourp by a.idCustomer“).setDate(0, statTimeBegin).setDate(1, statTimeEnd).scroll();
            //将查询结果放入List保存
            while(srs.next()){
                res.add(new TotalCharge(srs.getString(0), srs,getDouble(1), srs.getDate(2), srs.getDate(3)));
            }
        }catch(HibernateException he){
            ;//loging err..
            if(srs!=null){
                try{
                    srs.close();
                }catch(Exception e){
                    ;
                }
            }
        }finally{
            try{
                session.close();
            }catch(Exception e){
                ;
            }
        }
        return res;
    }