Question

Taking the following object model:

public abstract class Entity
{
    public Guid Id { get; set; }
}

public class Category : Entity
{
    public string Name { get; set; }

    public ICollection<LocalizedProperty> LocalizedProperties { get; set; }
}

public class Product : Entity
{
    public string Name { get; set; }

    public ICollection<LocalizedProperty> LocalizedProperties { get; set; }
}

public class LocalizedProperty : Entity
{
    public string CultureName { get; set; }
    public string PropertyName { get; set; }
    public string PropertyValue { get; set; }
}

Is it possible to use a type discriminator along with the entity’s Id as the foreign key. The idea is that the resultant LocalizedProperties table would be:

LocalizedProperties
-------------------
Id
EntityType
EntityId
CultureName
PropertyName
PropertyValue

I know this is possible using Table-per-subclass mapping where each of my “Localized” entities inherit from a base localized entity class, which in turn has the association with LocalizedProperty. However, I would rather not have this extra level of inheritance if the above is possible.

Thanks,
Ben

UPDATE

Thanks to Diego for providing the solution using confORM. For those of you using traditional mapping files, I have converted the example from http://fabiomaulo.blogspot.com/2010/11/conform-any-to-many.html

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" namespace="ConfOrm.UsageExamples.CreateXmlMappingsInBinFolder" assembly="ConfOrm.UsageExamples" xmlns="urn:nhibernate-mapping-2.2">
  <class name="Blog">
    <id name="Id" type="Guid">
      <generator class="guid.comb" />
    </id>
    <property name="Title" />
    <property name="Subtitle" />
    <set name="Tags" cascade="all" where="TagedItemClass = 'ConfOrm.UsageExamples.CreateXmlMappingsInBinFolder.Blog'">
      <key column="TagedItemId" foreign-key="none" />
      <one-to-many class="Tag" />
    </set>
  </class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" namespace="ConfOrm.UsageExamples.CreateXmlMappingsInBinFolder" assembly="ConfOrm.UsageExamples" xmlns="urn:nhibernate-mapping-2.2">
  <class name="Tag">
    <id name="Id" type="Guid">
      <generator class="guid.comb" />
    </id>
    <property name="Name" />
    <any id-type="Guid" name="TagedItem">
      <column name="TagedItemClass" />
      <column name="TagedItemId" />
    </any>
  </class>
</hibernate-mapping>

Answer 1

You can use <any>.

http://nhibernate.info/doc/nh/en/index.html#mapping-types-anymapping

For a full example, check http://fabiomaulo.blogspot.com/2010/11/conform-any-to-many.html. I think it’s exactly what you need.