NServiceBus and nvarchar(max)

Question

My Saga class is as follows:

public class SagaData : IContainSagaData
{
    [Unique]
    public virtual string SagaKey { get; set; }

    public virtual string Data { get; set; }

    #region IContainSagaData

    public virtual Guid Id { get; set; }

    public virtual string Originator { get; set; }

    public virtual string OriginalMessageId { get; set; }

    #endregion IContainSagaData
}

I'm persisting Sagas in SQL Server. The created table has the following structure:

CREATE TABLE [dbo].[SagaData](
    [Id] [uniqueidentifier] NOT NULL,
    [SagaKey] [nvarchar](255) NULL,
    [Data] [nvarchar](255) NULL,
    [Originator] [nvarchar](255) NULL,
    [OriginalMessageId] [nvarchar](255) NULL,
PRIMARY KEY CLUSTERED 
(
    [Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY],
UNIQUE NONCLUSTERED 
(
    [SagaKey] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

Data property (type of string) has been mapped to nvarchar(255). Obviously, when I assign more than 255 characters to that property it fails with message:

String or binary data would be truncated.

How can I force to make it nvarchar(max)?

I'm using NServiceBus 4.4.2.

Answer 1

The solution is quite simple. I added a HBM file for that class, set it as Embedded Resource and NHibernate automatically loaded it. This is how it looks:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
                   assembly="LuxMed.BackEnd.CRM.B2C.NSB.Host"
                   namespace="LuxMed.BackEnd.CRM.B2C.NSB.Host.Sagas">
  <class name="SagaData">
    <id name="Id" />
    <property name="SagaKey" unique="true" />
    <property name="Data" type="StringClob" />
    <property name="Originator" />
    <property name="OriginalMessageId" />
  </class>
</hibernate-mapping>

type="StringClob" is what makes nvarchar(max) in DB.