我在使用Telerik的RadGrid时遇到了这个问题。我将主键设置为只读的绑定列。如果列是display="false"，它会工作得很好，但readonly="true"导致了问题。我通过将绑定列display=false并添加一个单独的模板列来解决这个问题

<telerik:GridBoundColumn HeaderText="Shouldnt see" Display="false" 
     UniqueName="Id" DataField="Id">
</telerik:GridBoundColumn>
<telerik:GridTemplateColumn HeaderText="Id" UniqueName="IdDisplay">
    <ItemTemplate>
        <asp:Label ID="IDLabel" runat="server" 
            Text='<%# Eval("Id") %>'></asp:Label>                               
    </ItemTemplate>
</telerik:GridTemplateColumn> 

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.

我得到了同样的错误，因为PK的一部分是datetime列，而插入的记录使用了datetime。现在作为这一列的值。实体框架将以毫秒级精度插入值，然后以毫秒级精度查找刚刚插入的值。然而，SqlServer将该值舍入到秒精度，因此实体框架无法找到毫秒精度值。

解决方案是截断DateTime中的毫秒。在插入之前。

Got the same problem when removing item from table(ParentTable) that was referenced by another 2 tables foreign keys with ON DELETE CASCADE rule(RefTable1, RefTable2). The problem appears because of "AFTER DELETE" trigger at one of referencing tables(RefTable1). This trigger was removing related record from ParentTable as result RefTable2 record was removed too. It appears that Entity Framework, while in-code was explicitly set to remove ParentTable record, was removing related record from RefTable1 and then record from RefTable2 after latter operation this exception was thrown because trigger already removed record from ParentTable which as results removed RefTable2 record.

我今天遇到了一个类似的问题，我将在这里记录它，因为它不完全是乐观并发错误。

我正在将一个旧系统转换为一个新的数据库，它有几千个实体，我必须把它们脚本转移到新系统。然而，为了帮助理智，我选择保持原始的唯一id，所以是注入到新对象，然后尝试保存它。

我遇到的问题是，我使用MVC脚手架来创建基本存储库，他们在他们的UpdateOrInsert方法中有一个模式，基本上是在添加新实体或将其状态更改为modified之前检查是否设置了Key属性。

因为设置了Guid，所以它试图修改数据库中实际上不存在的行。

我希望这能帮助到其他人!

当公认的答案说“它不会最终覆盖应用程序不知道已经发生的更改”时，我很怀疑，因为我的对象是新创建的。但后来发现，有一个INSTEAD OF UPDATE, INSERT- TRIGGER附加到表中，它正在更新同一表的计算列。

一旦我将其更改为AFTER INSERT, UPDATE，它就可以正常工作了。