用NHibernate保存物体的正确方法是什么?

我刚开始休眠,刚开始映射到一个表,但是当我试图写一个对象时遇到了一些问题,这里是我的单元测试:

[TestFixture]
public class FacilityRepositoryTest : DatabaseRepositoryTestsBase
{
    private IRepository<Facility> repository = new Repository<Facility>();

    [Test]
    public void CanGetAllFacilities()
    {
        IList<Facility> allFacilities=repository.GetAll();
        Assert.IsNotNull(allFacilities);
        foreach (Facility facility in allFacilities)
        {
            Console.WriteLine(facility.NAME);
        }
    }
    [Test]
    public void CanCreateOneFacility()
    {
        try
        {
            repository.DbContext.BeginTransaction();
            Facility facility = new Facility();
            facility.FACILITY_CODE = "abc";
            facility.NAME = "Nameds";
            facility.ADDRESS = "Reinhardt strasse";
            repository.SaveOrUpdate(facility);
            repository.DbContext.CommitTransaction();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }
}

当我奔跑 CanCreateOneFacility ,我得到这个例外:

TestCase 'PJ1.TestUsingDevDb.PJ1Web.Data.FacilityRepositoryTest.CanCreateOneFacility'
failed: TearDown : NHibernate.TransactionException : Transaction not successfully started
--TearDown
en NHibernate.Transaction.AdoTransaction.CheckBegun()
en NHibernate.Transaction.AdoTransaction.Rollback()

我开始调试测试,没有异常被抛出,数据被记录,但是测试完成后,异常就出现了。

我做错什么了?这是保存对象的错误方法吗?