title: How to implement left join in JOIN Extension method
body: <p>I am trying to implement an outer join on this kind of query for the <code>p.Person</code> table.
  How would I do this?</p>
  
  <p>This example is taken from <a href="http://ashishware.com/DSLinqExample.shtml" rel="noreferrer">http://ashishware.com/DSLinqExample.shtml</a></p>
  
  <pre><code>var onlyinfo = p.Person
      .Where(n =&gt; n.FirstName.Contains('a'))
      .Join(p.PersonInfo,
          n =&gt; n.PersonId,
          m =&gt; m.PersonId,
          (n, m) =&gt; m)
      .ToArray&lt;Persons.PersonInfoRow&gt;();
  </code></pre>