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Hibernate框架5种检索方式
1.导航对象图检索方式：根据已经加载的对象导航到其他对象
2.OID检索方式：按照对象的OID来检索对象
3.HQL检索方式：使用面向对象的HQL查询语言
4.QBC检索方式：使用QBC(Query By Criteria)API来检索对象，这种API封装了基于字符串形式的查询语句，提供了更加面向对象的查询接口
5.本地SQL检索方式：使用本地数据库的SQL查询语句 这次重点讲解Criteria查询，首先我们先了解一下它。 Criteria 查询采用面向对象方式封装查询条件，又称为对象查询，对SQL语句进行封装
采用对象的方式来组合各种查询条件，由Hibernate 自动产生SQL 查询语句Criteria由Hibernate Session进行创建。
0. HibernateUtil辅助类的代码如下
package entity; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; public class HibernateUtil { private static final ThreadLocal sessionTL=new ThreadLocal(); private static Configuration conf; private final static SessionFactory sf; static{ try { conf=new Configuration().configure(); sf=conf.buildSessionFactory(); } catch (Exception ex) { ex.printStackTrace(); throw new ExceptionInInitializerError(ex); } } public static Session currentSession(){ Session session=(Session)sessionTL.get(); if (session==null) { session=sf.openSession(); sessionTL.set(session); } return session; } public static void closeSession(){ Session session=(Session)sessionTL.get(); sessionTL.set(null); session.close(); } }
1.无条件查询
/* * 无条件查询 */ @Test public void criTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Criteria criteria = session.createCriteria(Dept.class); List<Dept> list=criteria.list(); for (Dept dept : list) { System.out.println(dept.getDeptName()); } tx.commit(); HibernateUtil.closeSession(); }
2.比较运算
/* * 比较运算 * 条件查询 */ @Test public void criTestByname(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); List<Dept> list = session.createCriteria(Dept.class).add(Restrictions.eq("deptName", "测试部")).list(); for (Dept dept : list) { System.out.println(dept.getDeptName()); } tx.commit(); HibernateUtil.closeSession(); }
3.别名查询
/* * 别名查询 */ @Test public void criNamedTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Criteria criteria = session.createCriteria(Emp.class); criteria.createAlias("dept", "d");//把emp中dept属性命名为d List<Emp> list=criteria.add(Restrictions.eq("d.deptName", "测试部")).list(); for (Emp emp : list) { System.out.println(emp.getEmpName()); } tx.commit(); HibernateUtil.closeSession(); }
4.范围运算
/* * 范围运算 * Restrictions.in查询 */ @Test public void criInTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Criteria criteria = session.createCriteria(Emp.class); List<String> loclist=new ArrayList<>(); loclist.add("bj"); List<Emp> list=criteria.add(Restrictions.in("loc", loclist)).list(); for (Emp emp : list) { System.out.println(emp.getEmpName()); } tx.commit(); HibernateUtil.closeSession(); }
5.模糊查询
/* * 字符串模式匹配（模糊查询） */ @Test public void criLikeTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Criteria criteria = session.createCriteria(Emp.class); List<Emp> list= criteria.add(Restrictions.like("loc", "%b%")).list(); //下面和上面实现功能一样，只不过忽略大小写 //List<Emp> list= criteria.add(Restrictions.ilike("loc", "b",MatchMode.ANYWHERE)).list(); for (Emp emp : list) { System.out.println(emp.getEmpName()); } tx.commit(); HibernateUtil.closeSession(); }
6.逻辑运算
/* * 逻辑运算 and or not */ @Test public void criAndTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Criteria criteria = session.createCriteria(Emp.class).add(Restrictions.and(Restrictions.eq("empName", "小乐"),Restrictions.like("loc", "%b%"))); List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println(emp.getEmpNo()); } tx.commit(); HibernateUtil.closeSession(); }
7.动态查询
/* * 动态查询 */ @Test public void cridynamicTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Emp empcri=new Emp(); empcri.setEmpName("小乐"); empcri.setEmpNo(0); Criteria criteria = session.createCriteria(Emp.class); if (empcri.getEmpName()!=null) { //用户填写姓名作为条件 criteria.add(Restrictions.eq("empName", empcri.getEmpName())); } if (empcri.getLoc()!=null) { criteria.add(Restrictions.gt("empNo", empcri.getEmpNo())); } List<Emp> list = criteria.list(); for (Emp emp : list) { System.out.println(emp.getEmpNo()); } tx.commit(); HibernateUtil.closeSession(); }
8.排序
/* * 排序 */ @Test public void criOrderTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Criteria criteria = session.createCriteria(Emp.class); List<Emp> list = criteria.addOrder(Order.asc("empNo")).list(); for (Emp emp : list) { System.out.println(emp.getEmpName()); } tx.commit(); HibernateUtil.closeSession(); }
9.分页
/* * 分页 */ @Test public void criPageTest(){ Session session = HibernateUtil.currentSession(); Transaction tx = session.beginTransaction(); Criteria criteria = session.createCriteria(Emp.class); int pageIndex=2;//当前页码 int pageSize=2;//每页显示数据量 criteria.setFirstResult((pageIndex-1)*pageSize); criteria.setMaxResults(pageSize); List<Emp> list =criteria.list(); for (Emp emp : list) { System.out.println(emp.getEmpName()); } tx.commit(); HibernateUtil.closeSession(); }
10.detachedCriteria查询
/* * detachedCriteria查询 */ @Test public void detachedCriTest(){ Session session = HibernateUtil.currentSession(); DetachedCriteria dc=DetachedCriteria.forClass(Emp.class,"e"); dc.createAlias("e.dept", "d").add(Restrictions.eq("d.deptName", "测试部")); List<Emp> list=dc.getExecutableCriteria(session).list(); for (Emp emp : list) { System.out.println(emp.getEmpName()); } HibernateUtil.closeSession(); }
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原文地址：http://www.cnblogs.com/wth1129/p/5796287.html
