R – ‘Table with concrete class’ mapping using Fluent NHibernate’s auto mapping

fluent-nhibernatenhibernate

Does anyone whether it is possible to configure Fluent NHibernate to auto-map objects using 'Table with concrete class' inheritance. On looking at the auto-mappings (which I had written to file) I have a number of entities that derive from EntityBase but I would like the Id column to be on each table rather than on an EntityBase table.

<class name="EntityBase" table="EntityBase" xmlns="urn:nhibernate-mapping-2.2">
    <id name="Id" type="Int32" column="EntityBaseID">
      <generator class="identity" />
    </id>
    <joined-subclass name="CategoryType, ..., Version=1.0.0.0, Culture=neutral, PublicKeyToken=null">
      <key column="EntityBaseId" />
      <property name="CategoryTypeGUID">
        <column name="CategoryTypeGUID" />
      </property>
    </joined-subclass>
</class>

I scoured the Fluent docs but can't see anything related to this.

Thanks in advance.

Best Answer

Have you set the IsBaseType convention in your automapping? This particular convention defines what is deemed as simply a base class in your code, rather than something to be considered as part of an entity inheritance hierarchy.

AutoPersistenceModel
  /* regular config */
  .WithSetup(s =>
    s.IsBaseType = (type => type == typeof(EntityBase)));

Related Solutions

Inheritance Mapping with Fluent NHibernate

I know this is really old, but it is now pretty simple to set up fluent to generate the exact mapping you initially desired. Since I came across this post when searching for the answer, I thought I'd post it.

You just create your ClassMap for the base class without any reference to your subclasses:

public class ItemMap : ClassMap<Item>
{
    public ItemMap()
    {
        this.Table("Item");
        this.DiscriminateSubClassesOnColumn("ItemType");
        this.Id(x => x.ItemId, "ItemId");
        this.Map(x => x.FieldA, "FieldA");
    }
}

Then map your abstract subclass like this:

public class SubItemMap: SubclassMap<SubItemMap>
{
    public SubItemMap()
    {
        this.Map(x => x.FieldB);
    }
}

Then map your concrete subclasses like so:

public class ConcreteItemXMap : SubclassMap<ConcreteItemX>
{
    public ConcretItemXMap()
    {
        this.Join("ConcreteItemX", x =>
        {
            x.KeyColumn("ItemID");
            x.Map("FieldC")
        });
    }
}

Hopefully this helps somebody else looking for this type of mapping with fluent.

C# – Fluent NHibernate with Castle Windsor 2.0

There's probably a versioning conflict. Try getting the Castle and NH assemblies from the Castle build server.

Best Answer

Related Solutions

Inheritance Mapping with Fluent NHibernate

C# – Fluent NHibernate with Castle Windsor 2.0

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