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Criteria对象提供了一种面向对象的方式查询数据库。
Criteria对象需要使用Session对象来获得一个Criteria对象表示对一个
持久化类的查询
查询所有
Session session = HibernateUtil.getSession(); session.beginTransaction(); Criteria cri = session.createCriteria(User.class); List<User> list = cri.list(); for(User user : list) { System.out.println(user.getId() + " : " + user.getUsername()); } session.getTransaction().commit();
where
//1 Session session = HibernateUtil.getSession(); session.beginTransaction(); Criteria cri = session.createCriteria(User.class); //条件 cri.add(Restrictions.eq("username", "u1")); List<User> list = cri.list(); for(User user : list) { System.out.println(user.getId() + " : " + user.getUsername()); } session.getTransaction().commit(); //2 Session session = HibernateUtil.getSession(); session.beginTransaction(); Criteria cri = session.createCriteria(User.class); //条件 这是and效果 cri.add(Restrictions.eq("username", "u1")); cri.add(Restrictions.eq("password","123")); List<User> list = cri.list(); for(User user : list) { System.out.println(user.getId() + " : " + user.getUsername()); } session.getTransaction().commit(); //3 Session session = HibernateUtil.getSession(); session.beginTransaction(); Criteria cri = session.createCriteria(User.class); //条件 这是or效果 cri.add(Restrictions.or(Restrictions.eq("username", "u1"),Restrictions.eq("username", "jack"))); List<User> list = cri.list(); for(User user : list) { System.out.println(user.getId() + " : " + user.getUsername()); } session.getTransaction().commit(); // like Session session = HibernateUtil.getSession(); session.beginTransaction(); Criteria cri = session.createCriteria(User.class); /*MatchMode.ANYWHERE任何地方 MatchMode.START从开始 MatchMode.END表示u结尾的*/ cri.add(Restrictions.like("username", "u", MatchMode.ANYWHERE)); List<User> list = cri.list(); for(User user : list) { System.out.println(user.getId() + " : " + user.getUsername()); } session.getTransaction().commit();
分页
cri.setFirstResult(0);
cri.setMaxResults(5);
分组与统计
Creteria cri = session createCriteria(User.class); cri.setProjection(Projections.count("id")); Long count = (Long)cri.uniqueResult(); syso(count);
多个统计与分组
Creteria cri = session createCriteria(User.class); ProjectionList pList = Projections.projectionList(); pList.add(Projections.max("id")); pList.add(Projections.min("id")); cri.setProjection(pList); Object[] array = (Object[]) cri.uniqueResult(); System.out.println(array[0] + " : " +array[1]);
排序
Session session = HibernateUtil.getSession(); session.beginTransaction(); Criteria cri = session.createCriteria(User.class); cri.addOrder(Order.desc("id")); cri.addOrder(Order.asc("username")); List<User> list = cri.list(); for(User user : list) { System.out.println(user.getId() + " : " + user.getUsername()); } session.getTransaction().commit();
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当然也可以使用原生sql
Session session = HibernateUtil.getSession(); session.beginTransaction(); String sql = "select * from user"; SQLQuery query = session.createSQLQuery(sql); List<Object[]> list = query.list(); for(Object[] array : list) { System.out.println(array[0] + " : " + array[1]); } String sql = "select * from user"; SQLQuery query = session.createSQLQuery(sql).addEntity(User.class); List<User> list = query.list(); for(User user : list) { System.out.println(user.getId() + " : " + user.getUsername()); }
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原文地址：http://www.cnblogs.com/itliucheng/p/4462731.html
