NH-3095 - Cast from mapped long field to enum leads to 'Specified cast not valid'

[nhibernate-bot]

Serge SB created an issue — 23rd March 2012, 7:26:54:

I have an enum:

public enum Colors
{
  Red = 1,
  Green = 2,
  Blue = 3,
}

I have table in database, that maps to:

public class SomeEntity
{
  ...
  public virtual long Id { get; set; }
  public virtual long Color { get; set; }
  ...
}

And I have an info class, that I use for work:

public class SomeInfo
{
  public long Id { get; set; }
  public Colors MyColor { get; set; }
}

When I execute this:

var result = (from item in session.Query<SomeEntity>()
  select new SomeInfo
    {
      Id = item.Id,
      MyColor = (Colors) item.Color,
    }).List();

NHibernate throws exception 'Specified cast not valid'.

But when I change the declaration of enum from this:

public enum Colors

to this:

public enum Colors : long

everything works fine.

I've encountered this issue after migrating from 2.1.2GA NHibernate with linq2nhibernate extension to current 3.2.0GA version of NHibernate. So, 2.1.2 worked fine, but 3.2.0 throws that exception.

[hazzik]

Confirmed. The Linq provider produces a following transformation:

(object[] items) => new SomeInfo { Id = items[0], MyColor = (Color)items[1] }

So, the long is boxed to object and later is tried to be unboxed to Color.