我有一个场景，我想向我的实体添加一些标准属性。这意味着我将有 1 个 int 和 2 个字符串属性应用于所有相关实体。我有 100 多个映射文件，其中大多数（但不是全部）将成为这些新属性的主机。在类中很容易定义这一点；然而，在映射中，除了创建实用程序或 xslt 并应用它之外，我没有找到任何参考（如何在 hibernate 映射中定义可重用的 元素）。
但是我希望能够从这个“标准”映射中添加/修改/删除属性。
感谢您的任何回复
Edit1：我要添加的映射示例
<property name="TimeOfEdit" column="TimeOfEdit" type="DateTime" not-null="true"/>
<many-to-one name="EditedBy" column="FK_EditedBy" cascade="save-update" not-null="true" />
Edit2：
我删除了已接受的解决方案，因为 NH 2.1.1 XML 实体不起作用 (NH-1236) 并且 NH 将抛出“此 XML 文档中禁止 DTD”
I have a scenario that i want to add some standard properties to my entities. Meaning that i will have e.g. 1 int and 2 string properties applied to all relevant entities. I have over 100 mapping files and most but not all will be hosts to these new properties. In the classes its easy to define this; in the mappings however i've found no reference other than creating a utility or xslt and applying that (How to define reusable <generator> elements in hibernate mapping).
However i want to be able to add/modify/remove properties from this "standard" mapping.
thx for any replies
Edit1: an example of the mapping i want to add
<property name="TimeOfEdit" column="TimeOfEdit" type="DateTime" not-null="true"/>
<many-to-one name="EditedBy" column="FK_EditedBy" cascade="save-update" not-null="true" />
Edit2:
I removed the accepted solution because with NH 2.1.1 XML Entities are not working (NH-1236) and NH will throw a "DTD is prohibited in this XML document"
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这取决于这些属性在您的类中的实现方式。
如果它们都在基类或接口中定义，您可以在基类或接口中将它们映射一次，然后使用
union-subclass进行派生。有一些限制。阅读NHibernate 文档中的这一章有关于它的内容。如果您决定将它们放在一个类中，则可以将它们映射为用户类型。这与组件类似，但您可以在用户类型中指定一些内容，例如类型名称、长度等。您仍然需要指定每个列名称。
还有另一种选择：您可以使用XML 实体。这是 NHibernate 支持的 XML 的一个相当原始的功能。阅读NH 参考文档中的这一章 中提到了这一点。
It depends on how these properties are implemented in your classes.
If they are all defined in a base class or interface, you could map them once in the base class or interface, and derive using
union-subclass. There are some limitations. Read this chapter in the NHibernate documentation about it.If you decide to put them together into a class, you could map them as a user type. This will be similar to a component, but you could specify some things like type names, lengths and others in the user type. You still need to specify each column name.
There is another option: you could use XML entities. This is a rather primitive feature from XML which is supported by NHibernate. Read this chapter in the NH reference documentation where it is mentioned.
为您的具体情况创建特殊的代码生成器是您唯一的选择。
Creating a special code generator for your specific case is your only option.
选项 1：
- 在基类中定义这 3 个属性
- 让您的实体从此基类继承 -
设置“每个类层次结构表”
选项 2：
- 将这 3 个属性定义为组件。
- 您可以将这 3 个属性的映射放在一个可重复使用的文件中。
Option 1:
-Define these 3 properties in a base class
-have your entities inherit from this base
-set up 'table per class hierarchy'
Option 2:
-Define these 3 properties as a component.
-You can have the mapping for these 3 properties in one file that is reused.
你可以看看 fluenceNHibernate，它会简化你的映射工作。使用自动映射，您可能只需要一个抽象基类来定义这些属性。
You might take a look at fluentNHibernate, It will simplify the mapping work for you. With With auto mapping you may only need an abstract base class to define these properties.
似乎唯一要做的就是使用动态映射（http://ayende.com/Blog/archive/2008/05/01/Dynamic-Mapping-with-NHibernate.aspx），
因为我已经定义了我的实体的接口将用于新属性（假设是 IAuditable），只需在 NH 会话初始化时运行适当的代码
，然后
将其连接起来并准备使用即可
对于大约 85 个类，性能影响可以忽略不计
It seems that the only to do this, is to use Dynamic Mapping (http://ayende.com/Blog/archive/2008/05/01/Dynamic-Mapping-with-NHibernate.aspx)
as such since i've already defined an interface that my entities will use for the new properties (lets say IAuditable) its just a matter of running the appropriate code at the NH-session initialization
and then
to have it wired up and ready to be used
for about 85 classes the performance impact is negligible