在流利的nHibernate中使用派生类 [英] Use a derived class in fluent nHibernate

问题描述

我有两个共享公共领域的表。而不是重新映射所有这些，我想有一个共同的领域的基类。对于POCO来说，这很简单：

  class Base 
 {
 public string commonField {get; set;} 
} 
类派生：Base 
 {
 public string specificField {get; set;} 
} 
 class OtherDerived：Base 
 {
 public string specificOtherField {get; set;} 
} 
  

请注意，没有这样的东西作为基地的表。它只是拥有许多共同的几个表中共享的领域。是的，我知道这是不正常的，但这是我必须处理。

我的问题是 - 是否有一种方法来实现这个流利的nHibernate没有复制映射这些公共属性的代码？

解决方案

您可以继承 ClassMap 来做到这一点。我会做类似以下的事情：

  public class BaseMap< T> ：ClassMap< T> T：Base 
 {
 public BaseMap（）
 {
 Map（x => x.commonField，COMMON_FIELD）; 
} 
} 
 
 public class DerivedMap：BaseMap< Derived> 
 {
 public DerivedMap（）
 {
表（DERIVED_TABLE）; 
 Polymorphism.Explicit（）; //你可能想用你的情况。 
 Map（x => x.DerivedField，DERIVED_FIELD）; 
 
 
 
 
 $ b $ p $注意$  Polymorphism.Explicit （）; 以上。在你的情况下，我想你会想要这个。
 
 
 
  http://www.nhforge.org/doc/nh/en/#mapping-declaration-class  
 
I have two tables which share common fields.  Rather than re-map all of these I would like to have a base class with the common fields.  For POCO this is simple:
class Base
{
   public string commonField {get;set;}
}
class Derived : Base
{
   public string specificField {get;set;}
}
class OtherDerived : Base
{
   public string specificOtherField {get;set;}
}
Note that there is no such thing as a table for "base".  It just holds lots of common fields shared among several tables.  Yes, I know this is not well normalized, but it's what I have to work with.

My question is - is there a way to implement this in fluent nHibernate without having to duplicate the code that maps those common properties?
解决方案
You can inherit from ClassMap to do this.  I would do something like the following:
public class BaseMap<T> : ClassMap<T> where T : Base
{
    public BaseMap()
    {
        Map(x => x.commonField, "COMMON_FIELD");
    }
}

public class DerivedMap : BaseMap<Derived>
{
    public DerivedMap()
    {
        Table("DERIVED_TABLE");
        Polymorphism.Explicit();  //You may want to use this in your case.
        Map(x => x.DerivedField, "DERIVED_FIELD");
    }
}
Notice the Polymorphism.Explicit(); above.  In your case I think you are going to want this.

http://www.nhforge.org/doc/nh/en/#mapping-declaration-class

                        
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