8_一对一唯一外键关联映射(双向).txt

hibernate 映射文件笔记 希望对大家有所帮助

                       Person<--->IdCard

一对一唯一外键关联双向，需要在另一端（idcard），添加<one-to-one>标签，
指示hibernate如何加载其关联对象，默认根据主键加载person，外键关联映射中，
因为两个实体采用的是person的外键维护的关系，所以不能指定主键加载person，
而要根据person的外键加载，所以采用如下映射方式：
<one-to-one name="person" property-ref="idCard"/>    <!--property-ref 指明根据idCard加载person-->



              IdCard 

	private int id;
	private String cardNo;
	private Person person;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

<hibernate-mapping >
     <class name="com.tcit.hibernate.IdCard">
          <id name="id">
              <generator class="native"/>
          </id>
          <property name="cardNo"/>
          <one-to-one name="person" property-ref="idcard"/>     <!--property-ref 指明根据idCard加载person-->

     </class>
</hibernate-mapping>
=====================================================


             Person 
	
	private int id;
	private String name;
	private IdCard idcard;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

<hibernate-mapping >
     <class name="com.tcit.hibernate.Person">
     	<id name="id">
			<generator class="native"/>
		</id>
		<property name="name"/>
		<many-to-one name="idcard" unique="true"/>
     </class>
</hibernate-mapping>