当基类是流利的nhibernate抽象时，如何实现每个具体类的表？ [英] how to achieve table per concrete class when base class is abstract in fluent nhibernate?

问题描述

我有以下情况：

$ p $ public abstract class BaseClass
{
public virtual int Id {得到;组};
公共虚拟字符串名称{get; set;}
}

public class FirstSubClass：BaseClass
{
//在这里的属性和行为
}

public class SecondSubClass：BaseClass
{
// SecondSubclass的属性这里
}

公共类ProcessStep
{
公共虚拟IList< BaseClass> ContentElements {get; set;}
}


用于映射我已经使用下面的代码片段： -

  this._sessionFactory = 
流利的.Configure（）。数据库（SQLiteConfiguration.Standard 
 .ConnectionString（@Data Source = SqliteTestSqlDataAccess.s3db; Version = 3; New = True; Pooling = True; Max Pool Size = 1;））
 .Mappings（m => m.AutoMappings.Add（AutoMap.Assembly（assemblyWithDomainClasses） .Conventions.Add（DefaultCascade.All（））））
 .ExposeConfiguration（BuildSchema）
 .BuildSessionFactory（）; 
  

默认情况下，fluent会忽略BaseClass的抽象基类。
但是正如在类 ProcessStep 中有属性ContentElements返回 IList ，我得到一个异常： -
NHibernate.MappingException：关联引用未映射如果我使用IncludeBase（typeof（BaseClass））包含基类，那么它工作正常，但它为BaseClass和派生类和记录创建一个表与FK-PK关系（每个子类的表）关联。
我想实现的是每个具体类的表。也就是说每个派生类都有它自己的表，其中将有基类中派生类+属性的所有属性。
任何想法如何实现它？

解决方案

由于我没有看到你的映射，让我提供我的。您可以通过这样做来实现这一点。

  public class BaseClassMap：ClassMap< BaseClass> 
 public BaseClassMap（）
 {
 / * 
 *身份生成器不能是本地的，因为子类对象应该是唯一的
 *所以使用HiLo或Guid或其他生成器将在子表上生成唯一的ID 
 * / 
 Id（x => x.Id）.GeneratedBy.Guid（）; 
 Map（x => x.Name）; 
 UseUnionSubclassForInheritanceMapping（）; //这是重要的 - 对派生类使用联合子类映射
 
 
 $ b public class FirstSubClassMap：SubclassMap< FirstSubClass> 
 {
 public FirstSubClassMap（）
 {
表（FirstSubClassTable）; 
 // FirstSubClass的映射属性
} 
} 
 
 public class SecondSubClassMap：SubclassMap< SecondSubClass> 
 {
 Public SecondSubClassMap（）
 {
表（SecondSubClassTable）; 
 // SecondSubClass的地图属性
} 
} 
  

i have the following scenario

public abstract class BaseClass
{
  public virtual int Id {get; set};
  public virtual string Name {get; set;}
}

public class FirstSubClass : BaseClass
{
   //properties and behaviour here
}

public class SecondSubClass : BaseClass
{
  //properties of SecondSubclass Here
}

public class ProcessStep
{
   public virtual IList<BaseClass> ContentElements {get; set;}  
}

for mapping i have used following code snippet :-

this._sessionFactory =
                          Fluently.Configure().Database(SQLiteConfiguration.Standard
                          .ConnectionString(@"Data Source=SqliteTestSqlDataAccess.s3db;    Version=3; New=True; Pooling=True; Max Pool Size=1;"))
                          .Mappings(m => m.AutoMappings.Add(AutoMap.Assembly(assemblyWithDomainClasses).Conventions.Add(DefaultCascade.All())))
                          .ExposeConfiguration(BuildSchema)
                          .BuildSessionFactory();

By default fluent will ignore the abstract base class that is BaseClass. But as in the class ProcessStep there is property ContentElements which returns IList , i am getting an exception:- NHibernate.MappingException : Association references unmapped class: BaseClass

If i include the base class using the IncludeBase(typeof(BaseClass)) then it works fine but it creates a table for BaseClass and Derived classes and the records are linked with FK-PK relationship(table per subclass). What i want to achieve is table per concrete class. that is each derive class will have it's own table where there will all properties of derived class + properties in the base class. Any idea how to achieve it?

解决方案

Since I haven't seen your mapping, let me provide mine. You could achieve this by doing like this

public class BaseClassMap:ClassMap<BaseClass>
{
    public BaseClassMap()
    {
        /*
         * Identity generator can't be native because subclass objects should be unique
         * So use HiLo or Guid or other generators which will generate unique id on the child tables
         */
        Id(x => x.Id).GeneratedBy.Guid(); 
        Map(x => x.Name);
        UseUnionSubclassForInheritanceMapping(); // This is important - uses union-subclass mappings for the derived classes
    }
}

public class FirstSubClassMap : SubclassMap<FirstSubClass>
{
    public FirstSubClassMap()
    {
        Table("FirstSubClassTable");
        // Map properties for FirstSubClass
    }
}

public class SecondSubClassMap : SubclassMap<SecondSubClass>
{
    public SecondSubClassMap()
    {
        Table("SecondSubClassTable");
        // Map properties for SecondSubClass
    }
}

这篇关于当基类是流利的nhibernate抽象时，如何实现每个具体类的表？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！