New transaction is not allowed because there are other threads running in the session LINQ To Entity

c# linq linq-to-entities
Nick LaMarca picture Nick LaMarca · Apr 10, 2012 · Viewed 83.3k times · Source

Any ideas on why this could be breaking?

foreach (var p in pp)
{
    ProjectFiles projectFile = (ProjectFiles)p;
    projectFile.Status = Constants.ProjectFiles_ERROR;
    projectFile.DateLastUpdated = DateTime.Now;
    context.SaveChanges();
}

I read that the workaround the issue, is to retrieve the results in one go before the foreach loop.

But didnt I do that? "pp" is the collection of results in my case

Answer

Guffa picture Guffa · Apr 10, 2012

The pp variable isn't a collection of objects, it's an enumerator that can return objects. While you use the enumerator, the source has to remain open.

Use the ToList method to realise the enumerator into a collection. That will read all items from the enumerator and close the connection to the source, so that you can use the connection for other things.

foreach (var p in pp.ToList())

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