hibernate 一对一关联关系 及其懒加载，总结

Posted 2020-06-13

一对一，则有主对象和从对象之区别

若无主对象，则从对象亦无存在之意义。

主对象为person

从对象为idcard

<hibernate-mapping package="cn.itcast.hibernate.domain">

    <class name="Person">
        <id name="id">
            <generator class="native" />
        </id>
        <property name="name" />
        <one-to-one name="idCard"/>
    </class>

</hibernate-mapping>

 

<hibernate-mapping package="cn.itcast.hibernate.domain">

    <class name="IdCard" table="id_card">
        <id name="id">
            <generator class="foreign">
                <param name="property">person</param>
            </generator>
            
        </id>
        <property name="name"/>
         
        <one-to-one name="person" constrained = "true"/>
    </class>

</hibernate-mapping>

 constrained = "true"是约束，即为加上外键引用。