Hibernate hbm文件

<hibernate-mapping>
    <class name="demo.po.Booktype" table="booktype" catalog="book">
        <id name="tid" type="java.lang.Integer">
            <column name="tid" />
            <generator class="native" />
        </id>
        <property name="tname" type="java.lang.String">
            <column name="tname" length="30" not-null="true" />
        </property>

<!--inverse="true"，把控制权交给"N"'端，这样节约资源-->
<!-- cascade="delete"表示级联删除-->

        <set name="books" inverse="true" cascade="delete">
            <key>
                <column name="btype" not-null="true" />
            </key>
            <one-to-many class="demo.po.Book" />
        </set>
    </class>
</hibernate-mapping>