I am using the sharp architecture which also deploys FNH. The db schema sql code is generated during the testing like this:

[TestFixture]
    [Category("DB Tests")]
    public class MappingIntegrationTests
    {
        [SetUp]
        public virtual void SetUp()
        {
            string[] mappingAssemblies = RepositoryTestsHelper.GetMappingAssemblies();
            configuration = NHibernateSession.Init(
                new SimpleSessionStorage(),
                mappingAssemblies,
                new AutoPersistenceModelGenerator().Generate(),

"../../../../app/XXX.Web/NHibernate.config"); }

[TearDown]
public virtual void TearDown()
{
    NHibernateSession.CloseAllSessions();
    NHibernateSession.Reset();
}

[Test]
public void CanConfirmDatabaseMatchesMappings()
{
    var allClassMetadata = NHibernateSession.GetDefaultSessionFactory().GetAllClassMetadata();

    foreach (var entry in allClassMetadata)
    {
        NHibernateSession.Current.CreateCriteria(entry.Value.GetMappedClass(EntityMode.Poco))
             .SetMaxResults(0).List();
    }
}

/// <summary>
/// Generates and outputs the database schema SQL to the console
/// </summary>
[Test]
public void CanGenerateDatabaseSchema()
{
    System.IO.TextWriter writeFile = new StreamWriter(@"d:/XXXSqlCreate.sql");

    var session = NHibernateSession.GetDefaultSessionFactory().OpenSession();
    new SchemaExport(configuration).Execute(true, false, false, session.Connection, writeFile);
}

private Configuration configuration;

}

I am trying to use:

using FluentNHibernate.Automapping; 
using xxx.Core; 
using SharpArch.Data.NHibernate.FluentNHibernate; 
using FluentNHibernate.Automapping.Alterations; 
namespace xxx.Data.NHibernateMaps 

{ 
    public class x : IAutoMappingOverride<x> 
    { 
        public void Override(AutoMapping<Tx> mapping) 
        { 
            mapping.Map(x => x.text, 
"text").CustomSqlType("varchar(max)"); 
            mapping.Map(x => x.url, 
"url").CustomSqlType("varchar(max)"); 
        } 
    } 
} 

To change the standard mapping of strings from NVARCHAR(255) to varchar(max). This is not picked up during the sql schema generation.

I also tried:

mapping.Map(x => x.text, "text").Length(100000);

Any ideas?

Thanks.

Christian