Question

是否可以使用nhibernate引用子对象中的父对象？到目前为止我一直在做的是将父Id放在子类中，允许我确定任何子节点的父节点在运行时。

有人告诉我，我可以改为引用我孩子的整个父对象，而不仅仅是父ID，而不会遇到递归问题。

我目前所做的是：

Child child = (Child)session.Get(typeof(Child), childId);

然后我可以这样抓住我的parentId：

int parentId = child.ParentId;

我想做的是：

Child child = (Child)session.Get(typeof(Child), childId);

int parentId = child.**Parent**.Id;

string parentName = child.**Parent**.Name

以下是我如何定义课程的示例

public class Parent
{
public int Id { get; set; }
public string Name { get; set; }

// A list of child objects
public IList<Child> Children { get; set; }
}

public class Child
{
public int Id { get; set; }
public string Name { get; set; }
public int ParentId { get; set; } // this is what I use now 

// public Parent MyParent { get; set; } // this is what I want to use
}

我的nHibernate映射文件：

   <class name="Parent" table="parents" lazy="false">
        <id name="Id">
            <generator class="identity" />
        </id>
        <property name="Name" />
        <bag name="Children" cascade="all" lazy="false" >
            <key column="ParentId" />
            <one-to-many class="Child"/>
        </bag>

        <!-- Do I put anything in here to refer to my parent object in my child object?-->
    </class>


   <class name="Child" table="Children" lazy="false">
        <id name="Id">
            <generator class="identity" />
        </id>
        <property name="ParentId" />
        <property name="Name" />

        <!-- Do I put anything in here to refer to my parent object in my child object?-->
    </class>

感谢任何帮助！

Answer 1

确保这是可能的：

<!-- Set inverse to true on the one-to-many to tell 
     NHibernate this relation is mapped from both sides -->
<bag name="Children" cascade="all" lazy="false" inverse="true">
    <key column="ParentId" />
    <one-to-many class="Child"/>
</bag>

<class name="Child" table="Children" lazy="false">
    <id name="Id">
        <generator class="identity" />
    </id>
    <property name="ParentId" />
    <!-- Use this to map the Parent object -->
    <many-to-one name="MyParent" class="Parent" column="ParentId"/>
<property name="Name" />
    </class>

子类中的nhibernate引用父类

1 个答案: