Question

What is the new SetAttribute() in FNH mapping? I need to set my discriminator value on subclass because String is not preferred – old post

with NH 2.1.2.4000, FNH 1.1.0.689

public class BaseBuildingMap : ClassMap<BaseBuilding>
{
    public BaseBuildingMap()
    {
        Id(x => x.Id);
        DiscriminateSubClassesOnColumn<int>("BuildingType", -1);
    }
}

public class PowerStationMap : SubclassMap<PowerStation>
{
    public PowerStationMap()
    {
        Map(x => x.ElectricityProduction);
    }
}

NHibernate.MappingException: Could not format discriminator value to SQL string of entity Model.Test.PowerStation —> System.FormatException: Input string was not in a correct format.

I need to set SetAttribute("discriminator-value", "-1"); but there is no such method.

EDIT 1

Question: How to set discriminate column type for subclass with FNH?

Answer 1

public class PowerStationMap : SubclassMap<PowerStation>
{
    public PowerStationMap()
    {
        DiscriminatorValue((int)1);
        Map(x => x.ElectricityProduction);
    }
}

I’ve finally found my answer, it’s

SubclassMap<T>::DiscriminatorValue(object discriminatorValue);