Hibernate QBC学习举例

public void testQBC() {                            //      方法  说明     //      Restrictions.eq     ＝     //      Restrictions.allEq  利用Map来进行多个等于的限制     //      Restrictions.gt     ＞     //      Restrictions.ge     ＞＝     //      Restrictions.lt     ＜    //      Restrictions.le     ＜＝     //      Restrictions.between    BETWEEN    //      Restrictions.like   LIKE    //      Restrictions.in     in    //      Restrictions.and    and    //      Restrictions.or     or    //      Restrictions.sqlRestriction     用SQL限定查询     //介绍以下几个典型的用法，这样其他的也会用了                                                    /*            * 简单的加些限制条件进行搜索             * Restrictions.eq            */           /* Session session = factory.openSession();            Criteria criteria = session.createCriteria(User.class);            Criterion criterion1 = Restrictions.eq("addr", "dalian");            Criterion criterion2 = Restrictions.eq("name", "tie");            criteria.add(criterion1);            criteria.add(criterion2);            List users = criteria.list();           for(User user : users){            System.out.println(user.introduce());            System.out.println("**********************");            }*/                         /*            * Restrictions.allEq   利用Map来进行多个等于的限制             */           /* Session session = factory.openSession();            Criteria criteria = session.createCriteria(User.class);            Map para = new HashMap();            para.put("addr", "dalian");            para.put("name", "tie");            Criterion criterion1 = Restrictions.allEq(para);            criteria.add(criterion1);            List users = criteria.list();            for(User user : users){            System.out.println(user.introduce());            System.out.println("**********************");            }*/                                      /*            * Restrictions.sqlRestriction用SQL限定查询             * Restrictions.sqlRestriction()这里有三个重载的方法，            */       /*   Session session = factory.openSession();            Criteria criteria = session.createCriteria(User.class);   //1.     Criterion criterion1 =            Restrictions.sqlRestriction("{alias}.name='tie' and            {alias}.addr='dalian'");     //2.     Criterion criterion1 = Restrictions.sqlRestriction("alias}.name=?",            "tie", Hibernate.STRING);                          //3.     Object[] ob = {"tie","dalian"};            Type[] type = {Hibernate.STRING,Hibernate.STRING};              Criterion criterion1 = Restrictions.sqlRestriction("{alias}.name=?            and {alias}.addr=?", ob, type);            criteria.add(criterion1);            List users = criteria.list();            for(User user : users){            System.out.println(user.introduce());            System.out.println("**********************");            }*/                          /*            * 排序            */           /* Session session = factory.openSession();            Criteria criteria = session.createCriteria(User.class);            criteria.addOrder(Order.desc("age"));            List users = criteria.list();            for(User user : users){            System.out.println(user.introduce());            System.out.println("**********************");            }*/                          /*            * 求平均数            */           /* Session session = factory.openSession();            Criteria criteria = session.createCriteria(User.class);            criteria.setProjection(Projections.avg("age"));            List avg_ages = criteria.list();            for(Double avg_age : avg_ages){            System.out.println("avg_age:"+avg_age);            }*/                                      /*            * 分组            */           /* Session session = factory.openSession();            Criteria criteria = session.createCriteria(User.class);            criteria.setProjection(Projections.groupProperty("addr"));            List addrs = criteria.list();            for(String addr : addrs){            System.out.println(addr);            }*/                                      /*            *过个的条件，同时求平均数和分组             */           /* Session session = factory.openSession();            Criteria criteria = session.createCriteria(User.class);            ProjectionList projectionList = Projections.projectionList();            projectionList.add(Projections.groupProperty("addr"));            projectionList.add(Projections.avg("age"));            criteria.setProjection(projectionList);            List avgs = criteria.list();            for(Object[] avg : avgs){            System.out.println(avg[0]+":"+avg[1]);            }*/                         /*            * DetachedCriteria举例            *             */                   /*  DetachedCriteria detachedCriteria = DetachedCriteria                   .forClass(User.class);           detachedCriteria.add(Restrictions.eq("addr", "dalian"));             Session session = factory.openSession();           Criteria criteria = detachedCriteria.getExecutableCriteria(session);             List users = criteria.list();           for (User user : users) {               System.out.println(user.introduce());               System.out.println("**********************");           }*/            //  session.close();        }