Hibernate：1对1关系总结。

QQ和QQ空间是1对1关系：配置如下

一、主键关联，双方共同维护表关系，以主键关联

public class QQ {

	private Long id;
	 private QQZone zone;
}

public class QQZone {

	private Long id;
	private QQ qq;
}

<hibernate-mapping package="com.bohe.domain">

	<class name="QQ" table="qq">
		<id name="id" column="ID">
			<generator class="native" />
		</id>
		<one-to-one name="zone" />

	</class>

</hibernate-mapping>

<hibernate-mapping package="com.bohe.domain">

	<class name="QQZone" table="qqzone">
		<id name="id" column="ID">
			<generator class="native" />
		</id>
		<one-to-one name="qq" />

	</class>

</hibernate-mapping>

二、用many-to-one模仿one-to-one，qq表为主表，qqzone为从表

public class QQ {

	private Long id;
	 private QQZone zone;
}

public class QQZone {

	private Long id;
	private QQ qq;
}

<hibernate-mapping package="com.bohe.domain">

	<class name="QQ" table="qq">
		<id name="id" column="ID">
			<generator class="native" />
		</id>
		<one-to-one name="zone" />

	</class>

</hibernate-mapping>

<hibernate-mapping package="com.bohe.domain">

	<class name="QQZone" table="qqzone">
		<id name="id" column="ID">
			<generator class="native" />
		</id>

		<many-to-one name="qq" column="qq_id" unique="true"/>
	</class>

</hibernate-mapping>