Hibernate4.x之映射关系--一对一映射

1 <many-to-one name="mgr" class="com.yl.hibernate.one2one.foreign.Manager" column="MGR_ID" unique="true"></many-to-one>

1 <one-to-one name="dept" class="com.yl.hibernate.one2one.foreign.Department" property-ref="mgr"></one-to-one>

1 from
2     MANAGERS manager0_ 
3 left outer join
4     DEPARTMENTS department1_ 
5 on manager0_.MGR_ID=department1_.DEPT_ID

1 from
2     MANAGERS manager0_ 
3 left outer join
4     DEPARTMENTS department1_ 
5 on manager0_.MGR_ID=department1_.MGR_ID

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 4 <!-- Generated 2014-11-29 20:05:53 by Hibernate Tools 3.4.0.CR1 -->
 5 <hibernate-mapping>
 6     <class name="com.yl.hibernate.one2one.foreign.Department" table="DEPARTMENTS">
 7         <id name="deptId" type="java.lang.Integer">
 8             <column name="DEPT_ID" />
 9             <generator class="native" />
10         </id>
11         <property name="deptName" type="java.lang.String">
12             <column name="DEPT_NAME" />
13         </property>
14         
15         <!-- 使用many-to-one 的方式来映射1-1关联关系 -->
16         <many-to-one name="mgr" class="com.yl.hibernate.one2one.foreign.Manager" column="MGR_ID" unique="true"></many-to-one>
17         
18     </class>
19 </hibernate-mapping>

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 4 <!-- Generated 2014-11-29 20:05:53 by Hibernate Tools 3.4.0.CR1 -->
 5 <hibernate-mapping>
 6     <class name="com.yl.hibernate.one2one.foreign.Manager" table="MANAGERS">
 7         <id name="mgrId" type="java.lang.Integer">
 8             <column name="MGR_ID" />
 9             <generator class="native" />
10         </id>
11         <property name="mgrName" type="java.lang.String">
12             <column name="MGR_NAME" />
13         </property>
14         
15         <!-- 映射1-1的关联关系：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 -->
16         <!-- 没有外键的一端需要使用one-to-one元素，该元素使用property-ref 属性指定使用被关联实体主键以外的字段作为关联字段 -->
17         <one-to-one name="dept" class="com.yl.hibernate.one2one.foreign.Department" property-ref="mgr"></one-to-one>
18         
19         
20         
21     </class>
22 </hibernate-mapping>

1 <id name="deptId" type="java.lang.Integer">
2     <column name="DEPT_ID" />
3     <!-- 使用外键的方式来生成当前的主键 -->
4     <generator class="foreign">
5         <!-- property属性指定使用当前持久化类的哪一个属性的主键作为外键 -->
6         <param name="property">mgr</param>
7     </generator>
8 </id>

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 4 <!-- Generated 2014-11-29 20:05:53 by Hibernate Tools 3.4.0.CR1 -->
 5 <hibernate-mapping>
 6     <class name="com.yl.hibernate.one2one.primary.Department" table="DEPARTMENTS">
 7         <id name="deptId" type="java.lang.Integer">
 8             <column name="DEPT_ID" />
 9             <!-- 使用外键的方式来生成当前的主键 -->
10             <generator class="foreign">
11                 <!-- property属性指定使用当前持久化类的哪一个属性的主键作为外键 -->
12                 <param name="property">mgr</param>
13             </generator>
14         </id>
15         <property name="deptName" type="java.lang.String">
16             <column name="DEPT_NAME" />
17         </property>
18         
19         <one-to-one name="mgr" class="com.yl.hibernate.one2one.primary.Manager" constrained="true"></one-to-one>
20     </class>
21 </hibernate-mapping>

 1 <?xml version="1.0"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 3 "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 4 <!-- Generated 2014-11-29 20:05:53 by Hibernate Tools 3.4.0.CR1 -->
 5 <hibernate-mapping package="com.yl.hibernate.one2one.primary">
 6     <class name="Manager" table="MANAGERS">
 7         <id name="mgrId" type="java.lang.Integer">
 8             <column name="MGR_ID" />
 9             <generator class="native" />
10         </id>
11         <property name="mgrName" type="java.lang.String">
12             <column name="MGR_NAME" />
13         </property>
14         
15         <!-- 
16             采用foreign主键生成器策略的一端增加one-to-one元素映射关联属性，
17             其one-to-one节点还应增加constrained="true"属性；以使当前的主键上添加外键约束
18          -->
19         <one-to-one name="dept" class="Department" property-ref="mgr"></one-to-one>
20         
21         
22         
23     </class>
24 </hibernate-mapping>