title: Only primitive types or enumeration types are supported in this context
body: <p>I've seen lots of questions on this topic, but I haven't been able to sort through any of them that actually solve the issue I'm seeing.  I have an activities entity that tracks which employee it is assigned to as well as which employee created the record and updated it.  If I remove the `where a.AssignedEmployee == currentUser' line of code, I don't get the run time error below.</p>
  
  <blockquote>
    <p>Unable to create a constant value of type 'DataModels.Employee'. Only
    primitive types or enumeration types are supported in this context.</p>
  </blockquote>
  
  <h2>CONTROLLER</h2>
  
  <pre><code>var query = from a in db.Activities
              where a.AssignedEmployee == currentUser
              where a.IsComplete == false
              orderby a.DueDate
              select a;
  return View(query.ToList());
  </code></pre>
  
  <h2>VIEW</h2>
  
  <pre><code>@model IEnumerable&lt;Data.DataModels.Activity&gt;
  ..........
  </code></pre>