Hibernate 集中常用的查询方式

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Hibernate一共有四种查询方式：

主键查询,HQL查询(hibernate特有的查询(实体)),QBC查询(完全面向对象的查询(实体)),SQL查询(数据库表)

package cn.itcast.hello;import java.util.List;import org.hibernate.Criteria;import org.hibernate.Query;import org.hibernate.SQLQuery;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.classic.Session;import org.hibernate.criterion.Criterion;import org.hibernate.criterion.Restrictions;import org.junit.Test;public class AppTest3 {private static SessionFactory factory;static{factory=new Configuration().configure().buildSessionFactory();//链式调用}//主键查询@Testpublic void  testQueryById(){Session session = factory.openSession();Transaction transaction = session.beginTransaction();//主键查询Employee emp = (Employee) session.get(Employee.class, 1);System.out.println(emp);transaction.commit();session.close();}//HQL查询@Testpublic void  testQuery(){Session session = factory.openSession();Transaction transaction = session.beginTransaction();Query query = session.createQuery("from Employee");//这里是JavaBean中的属性不是数据库的List list = query.list();System.out.println(list);transaction.commit();session.close();}//完全面向对象的查询@Testpublic void testQBC(){Session session = factory.openSession();Transaction transaction = session.beginTransaction();Criteria criteria = session.createCriteria(Employee.class);//条件criteria.add(Restrictions.eq("empName", "韩玮"));List list = criteria.list();System.out.println(list);transaction.commit();session.close();}@Testpublic void testSQL(){Session session = factory.openSession();Transaction transaction = session.beginTransaction();//把查询的每一行记录封装成对象添加到集合中SQLQuery query = session.createSQLQuery("select * from employee").addEntity(Employee.class);List list = query.list();System.out.println(list);transaction.commit();session.close();}}

运行结果一致：

Hibernate: select employee0_.id as id0_0_, employee0_.empName as empName0_0_, employee0_.workDate as workDate0_0_ from employee employee0_ where employee0_.id=?
Employee [id=1, empName=韩玮, workDate=2015-07-26 23:07:29.0]

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