title: Type Inference failed in a call to 'join' on nullable and non-nullable int
body: <p>In my Linq, I am trying to make an inner join to a nullable field. Employee and Department have a relation, Department may have an EmployeeID or may have a null. So what would be my join, if i want only the records that satisifed the inner join (no result for null EmployeeIDs):</p>
  
  <pre><code>var result = from emp in employees
               join dept in departments
               on new { Source = emp.EmployeeID }
               equals new { Source = dept.EmployeeID };
  </code></pre>
  
  <p>I am getting an exception:</p>
  
  <blockquote>
    <p>The type of one of the expressions in the join clause is incorrect.
    Type Inference failed in a call to 'join'.</p>
  </blockquote>
  
  <p>Thanks</p>