public void Save(object entity)
    {
        using (var transaction = Connection.BeginTransaction())
        {
        try
                {
                    SaveChanges();
                    transaction.Commit();
                }
                catch (OptimisticConcurrencyException)
                {
                    if (ObjectStateManager.GetObjectStateEntry(entity).State == EntityState.Deleted || ObjectStateManager.GetObjectStateEntry(entity).State == EntityState.Modified)
                        this.Refresh(RefreshMode.StoreWins, entity);
                    else if (ObjectStateManager.GetObjectStateEntry(entity).State == EntityState.Added)
                        Detach(entity);
                    AcceptAllChanges(); 
                    transaction.Commit();
                }
        }
    }

该问题是由以下两种原因之一引起的:-

You tried to update a row with one or more properties are Concurrency Mode: Fixed .. and the Optimistic Concurrency prevented the data from being saved. Ie. some changed the row data between the time you received the server data and when you saved your server data. You tried to update or delete a row but the row doesn't exist. Another example of someone changing the data (in this case, removing) in between a retrieve then save OR you're flat our trying to update a field which is not an Identity (ie. StoreGeneratedPattern = Computed) and that row doesn't exist.

我也有同样的问题，@webtrifusion的答案帮助我找到了解决方案。

我的模型使用实体ID上的绑定(排除)属性，这导致实体ID的值在HttpPost上为零。

namespace OrderUp.Models
{
[Bind(Exclude = "OrderID")]
public class Order
{
    [ScaffoldColumn(false)]
    public int OrderID { get; set; }

    [ScaffoldColumn(false)]
    public System.DateTime OrderDate { get; set; }

    [Required(ErrorMessage = "Name is required")]
    public string Username { get; set; }
    }
}   

对于那些使用AutoMapper的人 如果您正在更新一个实体，该实体具有指向另一个实体(或多个实体)的外键，请确保所有的外实体都将其主键设置为数据库生成(或对MySQL自动递增)。

例如:

public class BuyerEntity
{
    [Key]
    public int BuyerId{ get; set; }

    public int Cash { get; set; }

    public List<VehicleEntity> Vehicles { get; set; }

    public List<PropertyEntity> Properties { get; set; }

}

Vehicles和Properties存储在不同于Buyers的表中。当你添加一个新的买家时，AutoMapper和EF会自动更新车辆和属性表，所以如果你没有在这些表上设置自动增量(就像我没有)，那么你会看到来自OP的问题的错误。

我也面临着同样可怕的错误……:)然后我意识到我忘记设置一个

@Html。HiddenFor(model => model. userprofile . userid)

用于更新对象的主键!我容易忘记这个简单但非常重要的事情!

顺便说一下:HiddenFor是ASP的。净MVC。

您需要显式地包含主键的BoundField。如果你不想让用户看到主键，你必须通过css隐藏它:

    <asp:BoundField DataField="Id_primary_key" ItemStyle-CssClass="hidden" 
HeaderStyle-CssClass="hidden" />

其中'hidden'是css中的一个类，它的显示设置为'none'。