示例數據表：team(班級)、certificate(身份證)、student(學生)
Team.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="edu.dgut.ke.model.Team" table="TEAM"
lazy ="true" ><!-- 多對一的延遲加載設置 -->
<id name="id" type="java.lang.String">
<column name="ID" length="32" />
<generator class="uuid.hex" />
</id>
<property name="teamname" type="java.lang.String">
<column name="TEAMNAME" length="32" not-null="true" unique="true" />
</property>
<set name="students" inverse="true" cascade="all"
lazy="true" > <!-- 一對多的延遲加載設置 -->
<key>
<column name="TEAMID" length="32" not-null="true" />
</key>
<one-to-many class="edu.dgut.ke.model.Student" />
</set>
</class>
</hibernate-mapping>
Certificate.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="edu.dgut.ke.model.Certificate" table="CERTIFICATE"
lazy="true" ><!-- 一對一的延遲加載設置 -->
<id name="id" type="java.lang.String">
<column name="ID" length="32" />
<generator class="uuid">
</generator>
</id>
<property name="describe" type="java.lang.String">
<column name="`DESCRIBE`" length="50" not-null="true" />
</property>
<one-to-one name="student"
class="edu.dgut.ke.model.Student"
constrained="true" ><!-- 一對一的延遲加載設置 -->
</one-to-one>
</class>
</hibernate-mapping>
Student.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="edu.dgut.ke.model.Student" table="STUDENT"
lazy="true" >
<id name="id" type="java.lang.String">
<column name="ID" length="32" />
<generator class="uuid.hex" />
</id>
<many-to-one name="certificate"
class="edu.dgut.ke.model.Certificate"
unique="true"
column="cardId"
cascade="all"
>
</many-to-one>
<many-to-one name="team" class="edu.dgut.ke.model.Team">
<column name="TEAMID" length="32" not-null="true" />
</many-to-one>
<property name="studentname" type="java.lang.String">
<column name="STUDENTNAME" length="16" not-null="true" unique="true" />
</property>
</class>
</hibernate-mapping>
注意：對one-to-one 關系進行延遲加載和其他關系相比稍微有些不同。many-to-one 的延遲加載是在配置文件的class 標簽
上設置 lazy="true" ，one-to-many 和 many-to-many 的延遲加載是在 set 標簽中設置lazy="true"。而one-to-one 不只要在 classs
標簽設置 lazy="true"，而且要在one-to-one 標簽中設置constrained="true" 。
如果不設置constrained="true"，則一對一查詢使用默認的預先抓取策略(fetch="join")。