Hi,

I am trying to copy data between two identical databases, and keep getting a
could not delete collection: [Domain.User.Roles#<null>]
This appears to be problem with the identity columns, as if I remove them from the target database and change my id generator class attribute to read assigned everthing works. Please could someone tell me what I am doing wrong.

thanks

Jim


I have two databases with the following tables

CREATE TABLE [dbo].[users] (
[u_id] [int] IDENTITY (1, 1) NOT NULL ,
[username] [varchar] (50) NOT NULL
) ON [PRIMARY]


CREATE TABLE [dbo].[userroles] (
[u_id] [int] NOT NULL ,
[r_id] [int] NOT NULL
) ON [PRIMARY]
GO

CREATE TABLE [dbo].[roles] (
[r_id] [int] IDENTITY (1, 1) NOT NULL ,
[rolename] [varchar] (50) NOT NULL
) ON [PRIMARY]
GO

Mapping documents:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="Domain.User, Domain" table="users">

<id name="Id" column="u_id" type="Int32" unsaved-value="-1">
<generator class="identity" />
</id>

<property name="UserName" column="username" type="String" length="50" />

<bag name="Roles" table="userroles" cascade="all" lazy="false">

<key column="u_id" />
<many-to-many class="Domain.Role, Domain" column="r_id" outer-join="true" />
</bag>

</class>
</hibernate-mapping>

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="Domain.Role, Domain" table="roles" >

<id name="Id" column="r_id" type="Int32" unsaved-value="-1">
<generator class="identity" />
</id>

<property name="Name" column="rolename" type="String" length="50" />
</class>
</hibernate-mapping>

Here are my domain objects

public class Role
{
private int _id;
private string _name;

/// <summary>
///
/// </summary>
public Role()
{
this._id = -1;
this._name = null;
}

/// <summary>
///
/// </summary>
public virtual int Id
{
get { return this._id; }
set { this._id = value; }
}

/// <summary>
///
/// </summary>
public virtual string Name
{
get { return this._name; }
set { this._name = value; }
}
}

public class User
{
private int _id;
private string _userName;

private IList _roles;

/// <summary>
///
/// </summary>
public User()
{
this._id = -1;
this._roles = new ArrayList();
}

#region properties
/// <summary>
/// Property Id (int)
/// </summary>
public virtual int Id
{
get { return this._id; }
set { this._id = value; }
}

/// <summary>
/// Property Name (string)
/// </summary>
public virtual string UserName
{
get { return this._userName; }
set { this._userName = value; }
}

/// <summary>
///
/// </summary>
public virtual IList Roles
{
get { return this._roles; }
set { this._roles = value; }
}

#endregion

}

Code between sessionFactory.openSession() and session.close():

NHibernate.ISessionFactory sourceSessionFact = BuildFactory("SourceDB");
NHibernate.ISessionFactory destSessionFact = BuildFactory("TargetDB");

NHibernate.ISession sourceSession = sourceSessionFact.OpenSession();
NHibernate.ISession destSession = destSessionFact.OpenSession();

NHibernate.ITransaction tx = sourceSession.BeginTransaction();
Domain.User user = (Domain.User)sourceSession.Get(typeof(Domain.User), 1);
tx.Commit();
sourceSession.Close();

tx = destSession.BeginTransaction();
destSession.Replicate(user, NHibernate.ReplicationMode.Overwrite);
tx.Commit();
destSession.Close();
sourceSessionFact.Close();
destSessionFact.Close();

Full stack trace of any exception that occurs:

" at NHibernate.Collection.AbstractCollectionPersister.Remove(Object id, ISessionImplementor session)\r\n at NHibernate.Impl.ScheduledCollectionRemove.Execute()\r\n at NHibernate.Impl.SessionImpl.Execute(IExecutable executable)\r\n at NHibernate.Impl.SessionImpl.ExecuteAll(IList list)\r\n at NHibernate.Impl.SessionImpl.Execute()\r\n at NHibernate.Impl.SessionImpl.Flush()\r\n at NHibernate.Transaction.AdoTransaction.Commit()\r\n at WindowsApplication1.Form1.button1_Click(Object sender, EventArgs e) in I:\\testarea\\WindowsApplication1\\Form1.cs:line 33\r\n at System.Windows.Forms.Control.OnClick(EventArgs e)\r\n at System.Windows.Forms.Button.OnClick(EventArgs e)\r\n at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)\r\n at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)\r\n at System.Windows.Forms.Control.WndProc(Message& m)\r\n at System.Windows.Forms.ButtonBase.WndProc(Message& m)\r\n at System.Windows.Forms.Button.WndProc(Message& m)\r\n at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)\r\n at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)\r\n at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)\r\n at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)\r\n at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)\r\n at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)\r\n at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)\r\n at System.Windows.Forms.Application.Run(Form mainForm)\r\n at WindowsApplication1.Program.Main() in I:\\testarea\\WindowsApplication1\\Program.cs:line 19\r\n at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args)\r\n at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)\r\n at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()\r\n at System.Threading.ThreadHelper.ThreadStart_Context(Object state)\r\n at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)\r\n at System.Threading.ThreadHelper.ThreadStart()"


Hibernate version:
1.0.2.0

Name and version of the database you are using:
SQL Server 2000 sp4

I think I have finally cracked it. SaveOrUpdateCopy appears to work.
Thanks