hibernate学习（1）

（1）配置hebernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
        
<hibernate-configuration>
    <session-factory>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/heiniao</property>
        <property name="connection.username">root</property>
        <property name="connection.password"></property>

        <!-- SQL 方言 不同的数据库及版本  使用不同的方言-->
        <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
        <!-- 是否打印sql -->
        <property name="show_sql">true</property>
        <!-- 自动生成数据表策略   update为根据实体类生成数据库表-->
       <property name="hbm2ddl.auto">update</property>
       <!--指定实体类的配置文件 根据项目中实际路径配置-->
         <mapping  resource="com/heiniao/Model/UserModel.hbm.xml"/>  
    </session-factory>
</hibernate-configuration>

（2）对应数据库表的实体类  （get set 方法省掉）

public class UserModel {
    private int id;
    private int userCode ;
    private String userName ;
    private String password ;
    private String userType  ;
    private Date inputDate ;
    private String valid ;
｝

（3）配置实体类的映射文件  dynamic-update="true" 属性 为更新时只更新值修改的字段  <generator class="native" /> 为id生成策略为令数据库自己生成

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2016-5-16 23:16:22 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
    <class name="com.heiniao.Model.UserModel"  table="USER" dynamic-update="true">
        <id name="id" type="int">
            <column name="ID" />
            <generator class="native" />
        </id>
        <property name="userCode" type="int">
            <column name="USERCODE" />
        </property>
        <property name="userName" type="java.lang.String">
            <column name="USERNAME" />
        </property>
        <property name="password" type="java.lang.String">
            <column name="PASSWORD" />
        </property>
        <property name="userType" type="java.lang.String">
            <column name="USERTYPE" />
        </property>
        <property name="inputDate" type="java.util.Date">
            <column name="INPUTDATE" />
        </property>
        <property name="valid" type="java.lang.String">
            <column name="VALID" />
        </property>
    </class>
</hibernate-mapping>

（4） 执行操作

public static void main(String[] args) {  
            Configuration cfg = new Configuration();  
            cfg.configure();          
            ServiceRegistry  sr = new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();           
            SessionFactory  sf = cfg.buildSessionFactory(sr); 
            Session session =sessionFactory.openSession();  
            session.beginTransaction();  
            UserModel user = new UserModel();  
            user.setUserCode(1803062220);  
            user.setUserName("DennisHu");  
            user.setPassword("22");
            user.setUserType("1");
            user.setInputDate(null);
            user.setValid("1");
            session.save(user);  
            session.getTransaction().commit();  
            sessionFactory.close();  
      } 

（完成）

 查询为 UserModel user = (UserModel)session.get(UserModel.class,1);   1为数据的id

 更改实体类  user.setUserCode(9999);

 session.save(user);   hibernate自动发送Update语句

 session.getTransaction().commit();