Mapping for a reference to an enumerated type

kev160967 · **Posted:** Thu Jan 24, 2008 9:54 am

I'm getting an error with a mapping, and I'm not sure what I'm doing wrong. I have a table Actions which contains a column ActionType. This links to a table ActionTypes, which is basically a look up table. I have an enum as follows:

Code:

Namespace Rules.DAO

Partial Public Class ActionTypeList

  Public Enum enActionType
    StoredProcedure = 1
    Program = 2
    EDI = 3
    Code = 4
  End Enum

  {...}

which is referred to by the mapped class Action as follows:

Code:

Namespace Rules.DAO

  protected _actionType As ActionTypeList.enActionType
  public Overridable Property ActionType As ActionTypeList.enActionType 
    Get 
      return _actionType
    End Get
    Set(ByVal value As ActionTypeList.enActionType)
      _actionType = value
    End Set
  End Property

From reading the NHibernate docs, I should map this as a standard property with a type of the fully qualified name of my enum, so I have the following in the map file for Action:

Code:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="Rules.DAO" assembly="Rules.DAO">
  <class name="Rules.DAO.Action, Rules.DAO" table="Actions">
{...}
    <property name="ActionType" type="Rules.DAO.ActionTypeList.enActionType" />
{...}

When I try to create the session factory though I get the following error:

"could not interpret type: Rules.DAO.ActionTypeList.enActionType"

Can anyone tell me what I'm doing wrong? If I move the enum out of the class, and change the mapping accordingly it works, but I'd really prefer to have the enum defined within the class.

Kev

karlchu · **Posted:** Fri Jan 25, 2008 9:56 am

Enums are treated in NHibernate as the underlying integral type (Int32 in most cases). Just remove the type= attribute from the mapping. i.e.:

Code:

kev160967 · **Posted:** Fri Jan 25, 2008 11:34 am

Excellent, that did the trick. I think the documentation is incorrect though, as that indicates you specify the type and namespace.

benhyrman · **Joined:** Wed Jun 21, 2006 3:13 pm **Posts:** 110

It doesn't look like you're specifying the assembly for your type.

Like this:

<property name="Status" column="Status" type="KennelFinder.KennelStatus, KennelFinder" />

I could be wrong, but I think you need something like:

<property name="ActionType" type="Rules.DAO.ActionTypeList.enActionType, {Your assembly here}" />

kev160967 · **Posted:** Fri Jan 25, 2008 1:00 pm

Yes, you're right, sorry - the example I pasted in was one I'd been playing with. Even with the assembly specifed though, it still gave me the error. Omitting the type altogether resolves the problem. Also of note, my workaround of pulling the enum out of the class worked with the mapping as given.

Kev

benhyrman · **Joined:** Wed Jun 21, 2006 3:13 pm **Posts:** 110

Ok, I think I figured it out with the help of Reflector.

Pull your assembly into reflector and you will see that your enum, because it's inside of the class, is qualified with a +

Here is my code. I apologize that it's in C# and not VB.NET, but I don't see why it wouldn't resolve the same for you:

Code:

namespace PersonRage
{
   public partial class Person
   {
      public enum PersonStatus
      {
         Alive,
         NotAlive
      }

      private int id;
      private string name;
      private PersonStatus status;
      
      public int Id
      {
         get { return id; }
      }
      
      public string Name
      {
         get { return name; }
         set { name = value; }
      }
      
      public PersonStatus Status
      {
         get { return status; }
         set { status = value; }
      }
   }
}

And my mapping:

Code:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-lazy="false">
   <class name="PersonRage.Person, PersonRage" table="Person">
      <id name="Id" type="Int32" access="nosetter.camelcase" >
         <column name="personId" not-null="true" unique="true" />
         <generator class="native" />
      </id>
      
      <property name="Name" column="Name" />
      <property name="Status" column="Status" type="PersonRage.Person+PersonStatus, PersonRage" />
   </class>
</hibernate-mapping>

Of note, my type is PersonRage.Person+PersonStatus, PersonRage and not PersonRage.Person.PersonStatus, PersonRage as I would have expected. Please note the plus sign between Person and PersonStatus.

My test code, which worked rather well:

Code:

         DbSessionContext.Current.OpenSession();

         Person bob = new Person();

         bob.Name = "Bob Smith";
         bob.Status = Person.PersonStatus.Alive;

         DbSessionContext.Current.Save(bob);
         
         DbSessionContext.Current.CloseSession();

         DbSessionContext.Current.OpenSession();

         Person bobAgain = DbSessionContext.Current.Get<Person>(bob.Id);

         Console.WriteLine(bobAgain.Status.ToString());
         DbSessionContext.Current.CloseSession();

kev160967 · **Posted:** Mon Jan 28, 2008 8:44 am

Yes, that makes sense. Without the plus I guess there would be ambiguity between a namespace Person containing a PersonStatus and a class Person containing a PersonStatus. I'll modify my templates accordingly

Cheers,
Kev