对象表映射

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实体类--数据库表间的转换

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由于Hibernate的存储都是建立在对象基础上的，所以映射好实体类对象和数据库表是非常重要的，数据库表的设计也必须按照一定的规范来（冗余字段等就不允许存在?）

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本章的目录：

1.简单对象表映射

--搭建JUnit测试环境

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附：

搭建JUnit测试环境

1.去官网下载jar包

2.解压，复制junit-4.10.jar(我用的此时是4.10版本)到bin下的jar中

3.在项目名上右键→new→Source Folder→输入名称→finish

4.注意，你对哪个包进行测试，你就在测试下建立和那个包相同的包

5.建立测试类，需要在测试的方法前面加入”@Test”

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1.简单对象表映射，（单表无关联）

先把实体类贴出来（本人英文名jake,无需吐槽包名）

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package com.jake.hibernate.domain;
import java.util.Date;
public class Person {
	private long id;
	private String name;
	private Date birthday;

	public long getId() {
		return id;
	}

	public void setId(long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

}

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然后是映射文件:建议与实体类同包，名字为 ? 实体类名.hbm.xml

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<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.jake.hibernate.domain">
	<class name="Person" table="PERSON">
		<id name="id" column="id">
			<generator class="native" />
		</id>
		<property name="name" column="name" />
		<property name="birthday" type="timestamp" column="birthday" />
	</class>
</hibernate-mapping>

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?然后是配置文件(参考文档中给的)

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<?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>
		<!-- Database connection settings -->
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.url">jdbc:mysql://localhost:3306/hibernateTest</property>
		<property name="connection.username">root</property>
		<property name="connection.password">123456</property>
		<!-- JDBC connection pool (use the built-in) -->
		<property name="connection.pool_size">10</property>
		<!-- SQL dialect -->
		<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
		<!-- Enable Hibernate's automatic session context management -->
		<property name="current_session_context_class">thread</property>
		<!-- Disable the second-level cache  -->
		<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
		<!-- Echo all executed SQL to stdout -->
		<property name="show_sql">true</property>
		<!-- Drop and re-create the database schema on startup -->
		<property name="hbm2ddl.auto">update</property>
		<property name="show_sql">true</property>
		<property name="format_sql">true</property>
		<mapping resource="com/jake/hibernate/domain/Person.hbm.xml" />
		<!--
			<mapping resource="org/hibernate/tutorial/doma