ASP.NET MVC 简单事务添加

 //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