Entity Framework: “Store update, insert, or delete

Question

I am using Entity Framework to populate a grid control. Sometimes when I make updates I get the following error:

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.

I can't figure out how to reproduce this. But it might have something to do with how close together I make the updates. Has anyone seen this or does anyone know what the error message refers to?

Edit: Unfortunately I am no longer at liberty to reproduce the problem I was having here, because I stepped away from this project and don't remember if I eventually found a solution, if another developer fixed it, or if I worked around it. Therefore I cannot accept any answers.

Answer 1

Check whether you forgot the "DataKeyNames" attribute in the GridView. it's a must when modifying data within the GridView

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.datakeynames.aspx

Answer 2

i had the same problem, i figure out that was caused by the RowVersion which was null. Check that your Id and your RowVersion are not null.

for more information refer to this tutorial

http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/handling-concurrency-with-the-entity-framework-in-an-asp-net-mvc-application

Answer 3

I was facing this same scaring error... :) Then I realized that I was forgetting to set a

@Html.HiddenFor(model => model.UserProfile.UserId)

for the primary key of the object being updated! I tend to forget this simple, but very important thingy!

By the way: HiddenFor is for ASP.NET MVC.

Answer 4

I got that error when I was deleting some rows in the DB (in the loop), and the adding the new ones in the same table.

The solutions for me was, to dynamicaly create a new context in each loop iteration

Answer 5

While editing include the id or primary key of the entity as a hidden field in the view

ie

      @Html.HiddenFor(m => m.Id)

that solves the problem.

Also if your model includes non-used item include that too and post that to the controller

Answer 6

I got this error sporadically when using an async method. Has not happened since I switched to a synchronous method.

Errors sporadically:

[Authorize(Roles = "Admin")]
[HttpDelete]
[Route("file/{id}/{customerId}/")]
public async Task<IHttpActionResult> Delete(int id, int customerId)
{
    var file = new Models.File() { Id = id, CustomerId = customerId };
    db.Files.Attach(file);
    db.Files.Remove(file);

    await db.SaveChangesAsync();

    return Ok();
}

Works all the time:

[Authorize(Roles = "Admin")]
[HttpDelete]
[Route("file/{id}/{customerId}/")]
public IHttpActionResult Delete(int id, int customerId)
{
    var file = new Models.File() { Id = id, CustomerId = customerId };
    db.Files.Attach(file);
    db.Files.Remove(file);

    db.SaveChanges();

    return Ok();
}