<set name="Orders" table="Order" generic="true"

inverse="true" cascade="all">

<key column="CustomerId" foreign-key="FK_CustomerOrders"/>

<one-to-many class="Model.Order,Model"/>

</set>

 using Iesi.Collections.Generic;

 using System;

 using System.Linq;

 using System.Text;

 namespace Model

 {

     public class Customer

     {

         public virtual int CustomerId{ get; set; }

         public virtual String FirstName { get; set; }

         public virtual String LastName { get; set; }

         public virtual int Age { get; set; }

         public virtual int Version { get; set; }

         private ISet<Order> _orders = new HashedSet<Order>();

         public virtual ISet<Order> Orders

         {

             get { return _orders; }

             set { this._orders = value; }

         }

     }

 }

 <?xml version="1.0" encoding="utf-8" ?>

 <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"

                    namespace="Model"

                    assembly="Model"

                    default-lazy="true">

   <class name="Model.Customer, Model"

          discriminator-value="">

     <!--unsaved-value="" 主键表中不需要定义，而是需要在子表中定义-->

     <id name="CustomerId"

         column="CustomerId"

         type="Int32"

         unsaved-value="">

       <generator class="native" />

       <!-- unsaved-value used to be null and generator was increment in h2.0.3 -->

     </id>

     <!--version标签必须放在Id后面，否则出错-->

     <version name="Version"/>

     <property name="FirstName" >

       <column name="Firstname" length="" not-null="true"/>

     </property>

     <property name="LastName" type="String">

       <column name="Lastname"/>

     </property>

     <property name="Age" type="int">

       <column name="Age"/>

     </property>

     <!--双向关联时要用：

          inverse:由子表来维护关系,cascade:级联的关系 如果没有这个设置，

         插入Customer成功（即使现在Order插入Order抛异常，这时产生了垃圾数据，

         好的做法是用事务两者都能插入，避免垃圾数据的产生-->

     <!--经测试：只需要在主表配置cascade="all"，而子表不用配置cascade="all"，

     当删除主表实体时，子表的级联实体也会被删除-->

     <!--cascade有4种？？是吗？？，分别表示级联操作的4种操作：

       cascade = "none": 不能执行操作（有子时不给删父），经测试，为none时，添加父时没有自动添加子

       cascade = "all" : .级联（删父时删子），经测试，为all时，添加父时自动添加子，

                         .经测试，当设置cascade = "all"，MS SQL Server设置删除和更新操作虽然设置为：不执行操作，却被覆盖为联级

       cascade = "null": （删父时子设置为null），但经测试Nhibernate不支持这个值

       cascade = "？？？": 删父时子设置为默认值-->

     <set name="Orders" table="Order" generic="true"

           inverse="true" cascade="all">

       <key column="CustomerId" foreign-key="FK_CustomerOrders"/>

       <one-to-many class="Model.Order,Model"/>

     </set>

   </class>

 </hibernate-mapping>

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace Model

{

    public class Order

    {

        public virtual int OrderId { get; set; }

        public virtual DateTime OrderDate { get; set; }

        public virtual Customer Customer { get; set; }

        public virtual int Version { get; set; }

    }

}

<?xml version="1.0" encoding="utf-8" ?>

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"

                   namespace="Model"

                   assembly="Model"

                   default-lazy="true">

  <!--table ="[Order]"因为Order是SQL关键字，表名如果不添加中括号[]会抛异常-->

  <!--unsaved-value="" 主键表中不需要定义，而是需要在子表中定义

      unsaved-value id的类型是对象类型（如Int32等）unsaved-value不用显示标出来，因为unsaved-value默认值是null

  unsaved-value默认值是null，

  作用是：用于判断实体对象是新new的内存对象，还是应经持久化的对象，Nhibernate会从数据库中去获取

  该实体对象的Id与unsaved-value的值比较（如果持久化，id不等于null，当然也就不等于默认值为unsaved-value）：

  .实体对象的Id与unsaved-value的值，相等，说明调用Save（）添加，

  .实体对象的Id与unsaved-value的值，不相等相等，调用Update（），

     并在如果

  -->

  <class name="Model.Order, Model"

         table ="[Order]"

         discriminator-value="" lazy="false">

    <id name="OrderId"

        column="OrderId"

        type="Int32"

        unsaved-value="">

      <generator class="native" />

      <!-- unsaved-value used to be null and generator was increment in h2.0.3 -->

    </id>

    <!--version标签必须放在Id后面，否则出错-->

    <!--<version name="Version"/>-->

    <property name="OrderDate"  type="DateTime"  not-null="true">

      <column name="OrderDate" />

    </property>

    <many-to-one name="Customer" not-null="true">

      <column name="CustomerId" />

    </many-to-one>

  </class>

</hibernate-mapping>