title: Update all children entities, EF/Linq
body: <p>I have two tables A and B. Their relation is 1:N.
  I want to update one field in ALL the children tables, but I'm don't know what LINQ expression to use to do that -- shouldn't be too difficult.</p>
  
  <p>I was thinking something like:</p>
  
  <pre><code>parentEntity.childrens.All(..lambda expr..).field = value;
  </code></pre>
  
  <p>But obviously it's not working.</p>
  
  <p>I know the other option is a foreach(..), but I'd prefer L2E if possible.</p>