下面的代码为什么没有进行回滚            IDbConnection dbconn = db.CreateConnection();
            dbconn.Open();
            IDbTransaction Idbtran = dbconn.BeginTransaction();
            try
            {
                db.ExecuteNonQuery(CommandType.Text, "Insert Into [Author](FirstName,LastName) Values('han1','wei1')");                db.ExecuteNonQuery(CommandType.Text, "Update [Author] Set LastName = 'wei1xiu' where FirstName=han1");                Idbtran.Commit();
            }
            catch
            {
                Idbtran.Rollback();
            }
            finally
            {
                dbconn.Close();
            }