Update specific fields in Entity Framework
<p>I have a model:</p>
<pre><code>public class VR
{
    [Key]
    public int ID { get; set; }
    public string FullName { get; set; }
    public string CreatedBy { get; set; }
    public DateTime? Created { get; set; }
    public string ModifiedBy { get; set; }
    public DateTime? Modified { get; set; }
}
</code></pre>
<p>My controller's <code>Edit</code> function:</p>
<pre><code>    // POST: VRs/Edit/5
    [HttpPost]
    [ValidateAntiForgeryToken]
    public IActionResult Edit(VR vR)
    {
        if (ModelState.IsValid)
        {
            var Result = (from c in _context.MyVR.Where(c =&gt; c.ID == vR.ID) select c).Single();

            vR.Created = Result.Created;
            vR.CreatedBy = Result.CreatedBy;
            vR.ModifiedBy = User.Identity.Name;
            vR.Modified = DateTime.Now;
        
            _context.Update(vR);
            _context.SaveChanges();
            return RedirectToAction(&quot;Index&quot;);
        }
        return View(vR);
    }
</code></pre>
<p>and I get the error below:</p>
<blockquote>
<p>The instance of entity type '<code>UNTest.ViewModels.VR</code>' cannot be tracked because another instance of this type with the same key is already being tracked. For new entities consider using an <code>IIdentityGenerator</code> to generate unique key values.</p>
</blockquote>