public partial class AddEditSection : System.Web.UI.Page
    {
        int ID
        {
            get { return Request.QueryString["ID"] != null ? Convert.ToInt32(Request.QueryString["ID"]) : 0; }
        }

        Section s;
        ISectionDao sectionDao;
        protected void Page_Load(object sender, EventArgs e)
        {
            IDaoFactory daoFactory = new NHibernateDaoFactory();
            sectionDao = daoFactory.GetSectionDao();
            
            if (ID == 0)
                s = new Section();
            else
            {
                s = sectionDao.GetById(ID, false);

                if (IsPostBack)
                    return;

                TextBoxName.Text = s.Name;
                TextBoxOrd.Text = s.Ord.ToString();
               
            }
        }

        protected void LinkButtonSave_Click(object sender, EventArgs e)
        {
           
            try
            {
                s.Name = TextBoxName.Text;
                s.Ord = Convert.ToInt32(TextBoxOrd.Text);
                s.User = (UserProfile)Session["UserProfile"];
                              
                sectionDao.SaveOrUpdate(s);

            }
            catch (Exception ex)
            {
                LabelError.Text = ex.Message;
            }
        }

        protected void LinkButtonCancel_Click(object sender, EventArgs e)
        {
            Response.Redirect("Default.aspx");
        }
    }

/// <summary>
        /// For entities with automatatically generated IDs, such as identity, SaveOrUpdate may 
        /// be called when saving a new entity.  SaveOrUpdate can also be called to update any 
        /// entity, even if its ID is assigned.
        /// </summary>
        public T SaveOrUpdate(T entity) {
            NHibernateSession.SaveOrUpdate(entity);
            return entity;
        }

protected void btnAdd_OnClick(object sender, EventArgs e)
        {
            if (txtCustomerID.Text.Trim().Length == 5)
            {
                Customer newCustomer = new Customer(txtCompanyName.Text);
                newCustomer.SetAssignedIdTo(txtCustomerID.Text);
                newCustomer.ContactName = txtContactName.Text;

                IDaoFactory daoFactory = new NHibernateDaoFactory();
                ICustomerDao customerDao = daoFactory.GetCustomerDao();

                if (!IsDuplicateOfExisting(newCustomer, customerDao))
                {
                    customerDao.Save(newCustomer);
                    Response.Redirect("ListCustomers.aspx?action=added");
                }
                else
                {
                    lblMessage.Text =
                        "<span style=\"color:red\">The ID you provided is already in use.</span>
Please change the ID and try again.";
                }
            }
            else
            {
                lblMessage.Text =
                    "<span style=\"color:red\">The ID you provide must be exactly 5 characters long.</span>
Please change the ID and try again.";
            }
        }

public class Section : DomainObject<int>
    {
        
        public DateTime? DateInsert { get; set; }
        public DateTime? DateUpdate { get; set; }
        public int Ord { get; set; }

        string name;
        public string Name
        {
            get { return name; }
            set
            {
                Check.Require(!string.IsNullOrEmpty(value), "Наименование не должно быть пустым");
                name = value;
            }
        }

               
        public override int GetHashCode()
        {
            return (GetType().FullName + "|" +
                    Name + "|" +
                    Ord).GetHashCode();
        }

        public UserProfile User { get; set; }
        public IList<Test> Tests { get; set; }
    }

public partial class AddEditSection : System.Web.UI.Page
    {
        int id
        {
            get { return Request.QueryString["ID"] != null ? Convert.ToInt32(Request.QueryString["ID"]) : 0; }
        }

        SectionController controller = new SectionController();
        protected void Page_Load(object sender, EventArgs e)
        {
            controller.SetEntityInstance(id, (UserProfile)Session["UserProfile"]);

            if (IsPostBack)
                return;

            TextBoxName.Text = controller.Section.Name;
            TextBoxOrd.Text = controller.Section.Ord.ToString();
        }

        protected void LinkButtonSave_Click(object sender, EventArgs e)
        {
            LabelError.Text = "";
            try
            {
                controller.Section.Name = TextBoxName.Text;
                controller.Section.Ord = Convert.ToInt32(TextBoxOrd.Text);
                controller.Section.User = (UserProfile)Session["UserProfile"];

                controller.SaveOrUpdate();
            }
            catch (Exception ex)
            {
                LabelError.Text = ex.Message;
            }
            
        }

        protected void LinkButtonCancel_Click(object sender, EventArgs e)
        {
            Response.Redirect("Default.aspx");
        }
    }

if (e.Message.Contains("IX_MY_UNIQUE_INDEX"))
    

if (e.Message.StartsWith("INF"))
    throw new MyDataValidationException(e.Message.SubString(3), e);

// Бизнес объект, может быть кодогенерированным, в зависимости от
// используемых средств
class MyEntity 
{
    public int Value1 { get; set; }
    public int Value2 { get; set; }
    public int Value3 { get; set; }
}

class MyDataService
{
    // "это" вызываеш из LinkButtonSave_Click
    public void Save(MyEntity obj)
    {
        // тут валидация
        // тут сохранение в БД
    }
}

public class SectionController
    {
        public Section Section { get; set; }

        ISectionDao sectionDao;

        public void SetInstance(int id, UserProfile up)
        {
            IDaoFactory daoFactory = new NHibernateDaoFactory();
            sectionDao = daoFactory.GetSectionDao();

            if (id == 0)
                Section = new Section();
            else
            {
                Section = sectionDao.GetById(id, false);
                
            }
            Section.User = up;
        }

        public void SaveOrUpdate()
        {
            NHibernateSessionManager.Instance.BeginTransaction();
            try
            {
                
                if (sectionDao.GetUniqueByExample("Name", Section.Name, Section.ID)!= null)
                    throw new PostconditionException(String.Format("Раздел с наименованием [{0}] уже существует", Section.Name));
                
                sectionDao.SaveOrUpdate(Section);
                NHibernateSessionManager.Instance.CommitTransaction();
            }
            catch
            {

                NHibernateSessionManager.Instance.RollbackTransaction();
                NHibernateSessionManager.Instance.CloseSession();

                throw;
            }

        }
    }