NHibernate will save, but won´t load an entity
I´m receiving a very strange error with NHibernate 2.1.2.4000 GA and latest version of FluentNHibernate. I can save an entity but can´t load it back after a call to Flush() and Clear().
This is my entity:
public class Application
{
public int Id { get; set; }
public string Name { get; set; }
public string KeyName { get; set; }
public string Description { get; set; }
public string Url { get; set; }
public override bool Equals(object obj)
{
if (null != obj && obj is Application)
{
return ((Application)obj).Id == this.Id;
}
else
{
return base.Equals(obj);
}
}
}
My configuration Map:
public class ApplicationMap : ClassMap
{
public ApplicationMap()
{
Table("[Application]");
Not.LazyLoad();
Id(x => x.Id, "ApplicationId")
.GeneratedBy.Identity();
Map(x => x.Name, "ApplicationName")
.Nullable()
.Length(50);
Map(x => x.Description, "ApplicationDescription")
.Nullable()
.Length(200);
Map(x => x.KeyName, "ApplicationKeyName")
.Nullable()
.Length(50);
Map(x => x.Url, "ApplicationLink")
.Nullable()
.Length(50);
}
}
How I create my ISession:
var _sessionFactory = Fluently.Configure() .Database( SQLiteConfiguration.Standard.InMemory() .ProxyFactoryFactory(typeof(ProxyFactoryFactory))) .Mappings( m => m.FluentMappings.AddFromAssemblyOf()) .ExposeConfiguration(cfg => Config = cfg) .BuildSessionFactory(); var _session = _sessionFactory.OpenSession();
And this is the code that won´t work:
Application myApp = new Application()
{
Id = 1,
Description = "MyApp",
KeyName = "MyApp",
Name = "My App",
Url = "http://www.myapp.com"
};
_session.Save(myApp);
var idMyApp = myApp.Id;
_session.Flush();
_session.Clear();
_session = NHibernateHelper.CreateSession();
var a = _session.Load(idMyApp);
The Exception I get at the moment I try to Load the object back from database is:
Test method HNI.Portal.Test.MappingTests.RoleMap.CanCorrectMapRole threw exception: NHibernate.ObjectNotFoundException: No row with the given identifier exists[HNI.Portal.Core.Entities.Application#1].
and the StackTrace:
NHibernate.Impl.SessionFactoryImpl.DefaultEntityNotFoundDelegate.HandleEntityNotFound(String entityName, Object id) NHibernate.Event.Default.DefaultLoadEventListener.Load(LoadEvent event, IEntityPersister persister, EntityKey keyToLoad, LoadType options) NHibernate.Event.Default.DefaultLoadEventListener.ProxyOrLoad(LoadEvent event, IEntityPersister persister, EntityKey keyToLoad, LoadType options) NHibernate.Event.Default.DefaultLoadEventListener.OnLoad(LoadEvent event, LoadType loadType) NHibernate.Impl.SessionImpl.FireLoad(LoadEvent event, LoadType loadType) NHibernate.Impl.SessionImpl.Load(String entityName, Object id) NHibernate.Impl.SessionImpl.Load(Type entityClass, Object id) NHibernate.Impl.SessionImpl.Load[T](Object id)
I´m not sure if I should call Flush() and Clear() (still doing research on it), but I´m getting this error while writing tests with PersistenceSpecification. This is how PersistenceSpecification does on CheckList() assert to verify if a list is being correctly saved, which is not for me. I stepped into the code and got to this repro.
The application row is correctly inserted in the database but it won´t load again. It happens both with SqlServer and Sqlite.
Hope you guys can help me.
Thanks a lot!
You are setting the id but it's an Identity. You should not set it, SQL does that for you.
Instead of creating a new session use the same one, and retrieve using Get instead of Load.
On the difference between Load and Get: http://ayende.com/Blog/archive/2009/04/30/nhibernate-ndash-the-difference-between-get-load-and-querying-by.aspx
I think you're grabbing Id out of myApp too early. Try doing _session.Flush() before looking up Id . Since you're using an Identity Generator, NHibernate bubbles the generated Id back up to your object, but that doesn't happen until the session is flushed (usually at transaction commit-time).
Your using two differen ways to create the session?
NHibernateHelper.CreateSession();
and
_sessionFactory.OpenSession();
maybe you should try _sessionFactory.OpenSession(); to get a session for retrieval.
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