Duplicate key exception from Entity Framework?

catch (UpdateException ex)
{
    SqlException innerException = ex.InnerException as SqlException;
    if (innerException != null && innerException.Number == ??????)
    {
        // handle exception here..
    }
    else
    {
        throw;
    }
}

Put the correct number at ?????? that corresponds to unique constraint violation (I don't know it from the top of my head).

Now in C# 6.0 you should be able to do something like this:

catch (UpdateException ex) when ((ex.InnerException as SqlException)?.Number == ??????)
{
    // Handle exception here
}

Because I'm using EntityFramework with C#, I had to make a minor change to this - hope it helps anyone...

try
{
    await db.SaveChangesAsync();
}
catch (DbUpdateException ex)
{
    SqlException innerException = ex.InnerException.InnerException as SqlException;
    if (innerException != null && (innerException.Number == 2627 || innerException.Number == 2601))
    {
        //your handling stuff
    }
    else
    {
        throw;
    }
}

My issue came about because I needed DbUpdateException instead of UpdateException, and my InnerException object had an additional InnerException object that contained the Number I needed...