title: How to delete relational rows in WPF?
body: <p>I have Two table (Invoices-Receipts), every invoice have more than receipt (one to many relation)</p>
  
  <p>In WPF if I want To delete all Receipts for a specific Invoice in one step, How can I do that ?</p>
  
  <p>I have tried this:</p>
  
  <pre><code>     foreach (var item in _invoice.Receipts)
          _invoice.Receipts.Remove(item);
  </code></pre>
  
  <p>but it didn't work :(</p>
  
  <p>Thank you in advance.</p>