一对一关联关系基于主键、外键映射的例子

以Department 和Manager为例。怕忘了就当笔记

下面的是基于主键的

Department类

<hibernate-mapping>
    <class name="com.zcd.exercise.oneToOne.primary.Department" table="DEPARTMENTS">
        
        <id name="deptId" type="java.lang.Integer">
            <column name="DEPT_ID" />
            <generator class="foreign" >
                <param name="property">mgr</param>
            </generator>
        </id>
        
        <property name="deptName" type="java.lang.String">
            <column name="DEPT_NAME" />
        </property>
        
        <!-- 使用many-to-one 来映射1-1关联关系 -->
        <one-to-one name="mgr" class="com.zcd.exercise.oneToOne.primary.Manager" constrained="true"></one-to-one>
    </class>
</hibernate-mapping>

Manager类

<hibernate-mapping>
    <class name="com.zcd.exercise.oneToOne.primary.Manager" table="MANAGERS">
    
        <id name="mgrId" type="java.lang.Integer">
            <column name="MGR_ID" />
            <generator class="native" />
        </id>
        
        <property name="mgrName" type="java.lang.String">
            <column name="MGR_NAME" />
        </property>
        
        <!-- 映射1-1关联关系：在对应的数据表中已经有外键了，当前持久化类使用one-to-one进行映射 -->
        <!-- 没有外键的一端需要使用one-to-one元素， property-ref属性使用别关联实体主键以外的字段作为关联字段 -->
        <one-to-one name="dept" class="com.zcd.exercise.oneToOne.primary.Department"></one-to-one>
        
    </class>
</hibernate-mapping>

下面是基于外键的

Department类

<hibernate-mapping>
    <class name="com.zcd.exercise.oneToOne.foreign.Department" table="DEPARTMENTS">
        
        <id name="deptId" type="java.lang.Integer">
            <column name="DEPT_ID" />
            <generator class="native" />
        </id>
        
        <property name="deptName" type="java.lang.String">
            <column name="DEPT_NAME" />
        </property>
        
        <!-- 使用many-to-one 来映射1-1关联关系 -->
        <many-to-one name="mgr" class="com.zcd.exercise.oneToOne.foreign.Manager" column="MGR_ID" unique="true"></many-to-one>
        
    </class>
</hibernate-mapping>

Manager类

<hibernate-mapping>
    <class name="com.zcd.exercise.oneToOne.foreign.Manager" table="MANAGERS">
    
        <id name="mgrId" type="java.lang.Integer">
            <column name="MGR_ID" />
            <generator class="native" />
        </id>
        
        <property name="mgrName" type="java.lang.String">
            <column name="MGR_NAME" />
        </property>
        
        <!-- 映射1-1关联关系：在对应的数据表中已经有外键了，当前持久化类使用one-to-one进行映射 -->
        <!-- 没有外键的一端需要使用one-to-one元素， property-ref属性使用别关联实体主键以外的字段作为关联字段 -->
        <one-to-one name="dept" class="com.zcd.exercise.oneToOne.foreign.Department" 
        property-ref="mgr"></one-to-one>
        
    </class>
</hibernate-mapping>