QBC学习举例

java 代码

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<user></user> 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<user></user> 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<user></user> 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<user></user> 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<double></double> 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<string></string> 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<user></user> users = criteria.list();
        for (User user : users) {
            System.out.println(user.introduce());
            System.out.println("**********************");
        }*/

      //  session.close();
    }

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HQL的基础 | [转]QBC 之 DetchedCriteria

• 2007-11-30 20:36
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• 评论(3)
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3 楼 dtlxt 2010-09-21  

赞一个.

2 楼 happy_javaboy 2010-07-06  

1 楼 volking 2008-04-08  

不错呀...