title: Linq to SQL update multiple records in one query
body: <p>Given the code:</p>
  
  <pre><code>var q = db.TranslationProjectKeys.Where(c =&gt; c.ProjectID == forProject.ID);
  foreach (var key in q)
  {
      key.Live = false;
  }
  db.SubmitChanges();
  </code></pre>
  
  <p>If I run the SQL server profiler it shows dozens of <code>UPDATE....</code> SQL statements.  I believe this would be considerably faster if this query was executed with one <code>UPDATE</code> statement:</p>
  
  <pre><code>UPDATE TranslationProjectKeys SET Live = 0 WHERE ProjectID = x
  </code></pre>
  
  <p>Is there a way to make the query execute in this way?</p>
  
  <p>I'm wary of using <code>db.ExecuteCommand("...")</code> as I am aware the context can be cached which can cause some bugs.</p>