Question

I need to map a class which has a list of Enums to a db table, using NHibernate

here are the objects

public class Driver : IIdentity
{
    private IList<Licence> licences;

    /// <summary>
    /// The drivers licences
    /// </summary>
    public virtual IList<Licence> Licences
    {
        get
        {
            return this.licences;
        }
        set
        {
            this.licences = value;
        }
    }
    ..... rest of the class ....
}

//the enum
public enum Licence
{
    FivePersonCar = 5,
    SixPersonCar = 6
}

—————- here is the DB table

TABLE [dbo].[DriverLicence](
[DriverId] [int] NOT NULL,
[Level] [int] NOT NULL)

TABLE [dbo].[Driver](
[DriverId] [int] NOT NULL,
[Name] [varchar](150) NULL)

————-Here is my Fluent map for Driver

public class DriverMap : ClassMap<Driver>
{
    public DriverMap()
    {
        Id(x => x.Id).WithUnsavedValue(0).GeneratedBy.Identity();

        Map(x => x.Name);

        HasManyToMany(x => x.Licences)
            .WithTableName("DriverLicence")
            .AsElement("Level").AsBag();


        HasManyToMany(x => x.InsuredToDrive)
            .CollectionType<InsurancedList>()
            .WithTableName("InsuredWith");
    }

}

—– This generates the following HBM file

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-access="">
  <class name="Taxi.DomainObjects.Driver, Taxi.DomainObjects, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Driver`" xmlns="urn:nhibernate-mapping-2.2">
    <id name="Id" type="Int32" unsaved-value="0" column="DriverID">
      <generator class="identity" />
    </id>
    <property name="Name" type="String">
      <column name="Name" />
    </property>
    <bag name="Licences" table="DriverLicence">
      <key column="DriverId" />
      <many-to-many column="LicenceId" class="Taxi.DomainObjects.Licence, Taxi.DomainObjects, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
    </bag>
    <bag name="InsuredToDrive" collection-type="Taxi.DomainObjects.Collections.InsurancedList, Taxi.DomainObjects, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="InsuredWith">
      <key column="DriverId" />
      <many-to-many column="CarId" class="Taxi.DomainObjects.Car, Taxi.DomainObjects, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
    </bag>
  </class>
</hibernate-mapping>

---

here is my error

“An association from the table DriverLicence refers to an unmapped class: Taxi.DomainObjects.Licence”

anyone know what im doing wrong?

Answer 1

Enums are considered a primitive type by NHibernate, so you should not map using a many-to-many with a class attribute. In .hbm terms, you’d need something like this:

<bag name="Licences" table="DriverLicence">
  <key column="DriverId" />
  <element column="LicenceId" type="Taxi.DomainObjects.Licence, Taxi.DomainObjects, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
</bag>

Although in hbm mapping like this you can omit the long type attribute. My Fluent syntax is not very good, so I can’t help you there I’m afraid. This question may help further.