title: Linq to Entities SqlFunctions.DateDiff not supported
body: <p>I have the following code</p>
  
  <pre><code>DateTime now = DateTime.UtcNow;
  
  var allItemsOver64 = _inventoryContext.Items.Where(i =&gt; 
     (SqlFunctions.DateDiff("dd", i.PrimaryInsured.DoB, now) / 365.0) &gt;= 65);
  
  IQueryable&lt;Item&gt; items65To69 = allItemsOver64.Where(i =&gt;
     (SqlFunctions.DateDiff("dd", i.PrimaryInsured.DoB, now) / 365.0) &gt;= 65 &amp;&amp;
     (SqlFunctions.DateDiff("dd", i.PrimaryInsured.DoB, now) / 365.0) &lt;= 69);
  </code></pre>
  
  <p>But when I try and use allItemsOver64 thus Items65To69.Count() I get this error</p>
  
  <blockquote>
    <p>The expression 
    ((((Convert(DateDiff("dd", [10007].PrimaryInsured.DoB, 26/04/2012 15:03:09)) / 365) >= 65)
    And 
    ((Convert(DateDiff("dd", [10007].PrimaryInsured.DoB, 26/04/2012 15:03:09)) / 365) >= 65)) 
    And 
    ((Convert(DateDiff("dd", [10007].PrimaryInsured.DoB, 26/04/2012 15:03:09)) / 365) &lt;= 69)) 
    is not supported.</p>
  </blockquote>
  
  <p>What am I doing wrong?</p>