Fluent Nhibernate Enum Mapping - nhibernate

Question

I have some problem with enum mapping in fluent NHibernate. I know this question has been asked many times but I couldn't find any solution that worked for me. I'm newbie in NHibernate and it looks like I may have missed something simple and stupid. Here is my code.
public class DBPublication
{
public virtual int pub_id { get; set; }
public virtual PublicationStatuses status { get; set; }
...
}
public enum PublicationStatuses
{
on_moderation,
active,
...
}
public class DBPublicationMap : ClassMap<DBPublication>
{
public DBPublicationMap()
{
Table("content.publications");
Id(x => x.pub_id).GeneratedBy.Sequence("content.pub_sq");
Map(x => x.status);
...
}
}
postgres enum type
CREATE TYPE content.enum_publication_status AS ENUM('on_moderation', 'active', ...);
but when I try to save, postgres throws this
column "status" is of type content.enum_publication_status but expression is of type text
any suggestion?

Answer 1

Here is a working sample of configuring nhibernate to store enum field.
public class Entity
{
public virtual int id { get; set; }
public virtual SomeEnum EnumField { get; set; }
}
public enum SomeEnum
{
Value1,
Value2
}
class EntityMap : ClassMap<Entity>
{
public EntityMap()
{
Id(x => x.id).GeneratedBy.Native();
Map(x => x.EnumField);
}
}
class Program
{
static void Main(string[] args)
{
var factory = Fluently.Configure().Mappings(x => x.FluentMappings.AddFromAssemblyOf<Entity>())
.ExposeConfiguration(config => new SchemaExport(config).Create(false, true))
.Database(MsSqlConfiguration.MsSql2008.ConnectionString("Data Source=.;Initial Catalog=nhtest;Integrated Security=True"))
.BuildSessionFactory();
using (var session = factory.OpenSession())
{
using (var transaction = session.BeginTransaction())
{
var entity = new Entity();
entity.EnumField = SomeEnum.Value2;
session.Save(entity);
transaction.Commit();
}
}
}
}
In such case it is stored as strings in data base. If you want it be saved as integers, you need to change mapping for Enum field property to the following:
Map(x => x.EnumField).CustomType<int>();

Answer 2

Why are you creating enum types in progres? isn't this a maintenance-nightmare?
What does your configuration look like? Have you already tried using the conventions discribed here?
Looks like a simple casting error, so please consider using CustomType() / CustomSQLType() inside your mapping.

Answer 3

Simply add this class to your project:
public class PgEnumMapper<T> : NHibernate.Type.EnumStringType<T>
{
public override NHibernate.SqlTypes.SqlType SqlType
{
get { return new NHibernate.SqlTypes.SqlType(System.Data.DbType.Object); }
}
}
Then, you can use:
Map(x => x.status).CustomType<PgEnumMapper<PublicationStatuses>>();