ASP.NET MVC 简单事务添加

ASP.NET MVC 简单事务

 //实例化查询上下文
            using ( BookStoreEntities db = new  BookStoreEntities()) 
            {
                //找到需要价格和名称的数据实体对象
                var book = db.Books.FirstOrDefault(x => x.Title == "ASP.NET NVC 程序开发");
                if(book!=null)
                {
                    //更改属性值
                    book.Title = "ASP.NET NVC 程序开发";
                    book.Price = 30;
                    //保存更改,只有调用了SaveChannges()方法后,更新后的数据才能被写入数据库
                    db.SaveChanges();
                }
            }

            #region 使用事务新增
            using (BookStoreEntities db = new BookStoreEntities())
            {

                //声明事务对象
                System.Data.Common.DbTransaction tran = null;

                //手动打开链接并创建事务
                db.Conection.Open();

                tran = db.Connection.BeginTransaction();
                try
                {
                    var book = db.Books.FirstOrDefault(x => x.Title == "JavaScript语言与AJAX应用");
                    var order = new Orders() { Num = 1, Books = book, Address = "" };
                    db.AddToOrders(order);
                    db.SaveChanges();
                    order.Address = "中国湖北武汉";
                    db.SaveChanges();

                    //提交事务
                    tran.Commit();
                }
                //如果出现任何异常事务回滚

                catch (Exception)
                {
                    tran.Rollback();
                }
                finally
                {
                    //关闭连接
                    if (db != null && db.Connection.State != System.Data.ConnectionState.Closed)
                    {
                        db.Connection.Close();
                    }
                }

            #endregion