Auto-Mapping with Composite ID Not Working

I'm using the Sharp-Architecture framework and I have an entity that looks like this:

public class BaanAlternateItemKey : ValueObject
{
    public virtual string ItemId { get; protected set; }

    public virtual string AlternateItemId { get; protect开发者_如何学运维ed set; }
}

public class BaanAlternateItem : EntityWithTypedId<BaanAlternateItemKey>, IAlternateItem
{
    #region IAlternateItem Members

    public virtual IItem Item { get; protected set; }

    public virtual int Priority { get; protected set; }

    public virtual DateTime ExpirationDate { get; protected set; }

    #endregion
}

I have an auto mapping override that looks like this:

public class BaanAlternateItemAutoMappingOverride : IAutoMappingOverride<BaanAlternateItem>
{
    public void Override(AutoMapping<BaanAlternateItem> mapping)
    {
        mapping.ReadOnly();

        mapping.Table("VIEW_BAAN_ALTERNATE_ITEMS");

        mapping.CompositeId<BaanAlternateItemKey>(x => x.Id)
            .KeyProperty(x => x.ItemId, "ITEM_ID")
            .KeyProperty(x => x.AlternateItemId, "ALT_ITEM_ID");

        mapping.References<BaanItem>(x => x.Item, "ALT_ITEM_ID");
    }
}

I'm getting this exception:

----> NHibernate.MappingException : Could not determine type for: iPFS.Core.Baan.BaanAlternateItemKey, iPFS.Core, Version=0.0.4154.21888, Culture=neutral, PublicKeyToken=null, for columns: NHibernate.Mapping.Column(Id)

I have no idea what I'm doing wrong. Any suggestions?

UPDATE: If I map this using fluent mapping it works fine:

public class BaanAlternateItemMap : ClassMap<BaanAlternateItem>
{
    public BaanAlternateItemMap()
    {
        ReadOnly();

        Table("VIEW_BAAN_ALTERNATE_ITEMS");

        CompositeId<BaanAlternateItemKey>(x => x.Id)
            .KeyProperty(x => x.ItemId, "ITEM_ID")
            .KeyProperty(x => x.AlternateItemId, "ALT_ITEM_ID");

        Map(x => x.Priority, "PRIORITY");
        Map(x => x.ExpirationDate, "EXPIRATION_DATE").CustomType("Timestamp");

        References<BaanItem>(x => x.Item, "ALT_ITEM_ID");
    }
}

Is that shouldn't be that?:

public class BaanAlternateItemAutoMappingOverride : IAutoMappingOverride<BaanAlternateItem>
{
public void Override(AutoMapping<BaanAlternateItem> mapping)
{
    mapping.ReadOnly();

    mapping.Table("VIEW_BAAN_ALTERNATE_ITEMS");

    mapping.CompositeId<BaanAlternateItem>(x => x.Id) //are you mapping BaanAlternateItem right?
        .KeyProperty(x => x.ItemId, "ITEM_ID")
        .KeyProperty(x => x.AlternateItemId, "ALT_ITEM_ID");

    mapping.References<BaanItem>(x => x.Item, "ALT_ITEM_ID");
}
}

This error says that the mapping engine have no idea about any map for type BaanAlternateItemKey. So make sure that you have map for it.

I believe you'll want to convert the KeyProperty mapping for AlternateItemId to a KeyReference and then remove the References mapping as shown below. This assumes the Item has been mapped also and it has an Id property designated that matches the ALT_ITEM_ID value.

public class BaanAlternateItemAutoMappingOverride : IAutoMappingOverride<BaanAlternateItem>
{
    public void Override(AutoMapping<BaanAlternateItem> mapping)
    {
        mapping.ReadOnly();

        mapping.Table("VIEW_BAAN_ALTERNATE_ITEMS");

        mapping.CompositeId<BaanAlternateItem>(x => x.Id) //are you mapping BaanAlternateItem right?
            .KeyProperty(x => x.ItemId, "ITEM_ID")
            .KeyReference(x => x.Item, "ALT_ITEM_ID");
    }
}