title: Convert subquery in LINQ
body: <p>I have subquery in SQL like this  </p>
  
  <pre><code>SELECT A.DOCID 
  FROM mstdocs a, mstdocstats b 
  WHERE a.DOCID = b.DOCID 
  AND b.VID = '1' 
  AND A.DOCID NOT IN (SELECT a.docid 
                      FROM mstdocs a, mstdocstats b 
                      WHERE a.DOCID = b.DOCID 
                      AND b.VID = '1' 
                      AND a.VTAID = '2') 
  GROUP BY A.DOCID
  </code></pre>
  
  <p>How to convert that query in LINQ.
  thanks for any answer </p>