使用Entity Framework更新记录的更好方法

Question

我正在寻找一种更好的方法来使用Entity Framework更新记录.

以下是我现在使用的内容,其中playerFromModel是从View获取的数据.

public bool UpdatePlayer(PlayerEntity playerFromModel)
{
    bool updateSuccessfull = false;

    using (var context = new PlayerEntities())
    {
        var player = context.Player.Where(m => m.emailAddress == playerFromModel.EmailAddress).FirstOrDefault();

        if (player != null)
        {
            player.emailAddress = playerFromModel.EmailAddress;
            player.first_name = playerFromModel.FirstName;
            player.last_name = playerFromModel.LastName;
            player.alt_email_id1 = playerFromModel.AlternateEmailAddress;
            player.street = playerFromModel.Street;
            player.city = playerFromModel.City;
            player.state = playerFromModel.State;
            player.zip = playerFromModel.Zip;
            player.country_code = playerFromModel.CountryCode;
            player.phone1 = playerFromModel.Phone;

            try
            {
                context.SaveChanges();
                updateSuccessfull = true;
            }
            catch
            {
                updateSuccessfull = false;
            }
        }
    }

    return updateSuccessfull;
}

正如您所看到的,我必须手动映射每个字段以及我遵循的相同方法.

我当时认为必须有更好的方法来做到这一点.

请指导我这个.谢谢.

Answer 1

您可以使用TryUpdateModel.例如

    bool updateSuccessfull = false;
    using (var context = new PlayerEntities())
    {
        var player = context.Player.Where(m => m.emailAddress == playerFromModel.EmailAddress).FirstOrDefault();

        if (player != null)
        {
             //Beware this will try to map anything it can. This can be dangerous
            if(TryUpdateModel(player)){
            try
            {
                context.SaveChanges();
                updateSuccessfull = true;
            }
            catch
            {
                updateSuccessfull = false;
            }
         }
        }
    }
    return updateSuccessfull;
}

我不会在这里看到TryUpdateModel,ASP .NET MVC 3的真实示例.

你可以使用Automapper或MiBu所说的类似的东西.在此处创建ViewModel 链接,然后将其映射到实体

//Get a PlayerUpdate ViewModel     

       using (var context = new PlayerEntities())
    {
   // fetch the domain model that we want to update - BTW I'd use a repository pattern but that is another debate
        var player = context.Player.Where(m => m.emailAddress == playerFromModel.EmailAddress).FirstOrDefault();

        if (player != null)
        {

        // Use AutoMapper to update only the properties of this domain model
        // that are also part of the view model and leave the other properties unchanged
        AutoMapper.Map<UpdatePlayerViewModel , PlayerEntity>(viewModel, player);

           try
            {
                context.SaveChanges();
                updateSuccessfull = true;
            }
            catch
            {
                updateSuccessfull = false;
            }
    }

但是我认为更新实体属性是一件重要的事情,不应该自动完成.其他人也有同感.创建AutoMapper的Jimmy Bogard似乎并不认为它需要双向映射(但他说这部分是因为他们根据需要构建了AutoMapper)Stackoverflow上的类似答案说自己做.

这取决于应用程序的复杂性,但我会查看使用命令模式将消息发送到包含您的属性的适当处理程序并让处理程序更新它们.如果它成功了我们做一件事,如果不是我们做另一件事.MVC in Action中描述了相同的模式.看到类似的(这里是链接)[ http://www.paulstovell.com/clean-aspnet-mvc-controllers],这里是第二个链接