title: How to create html menu based on database table
body: <p>I have table category</p>
  
  <p><a href="https://i.stack.imgur.com/4nDTT.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4nDTT.jpg" alt="enter image description here"></a></p>
  
  <p>how to create second level menu where  <code>rodzic != 0</code> (rodzic means parent)</p>
  
  <ul>
  <li>Kominki na drewno
  
  <ul>
  <li>Atra</li>
  <li>Jotul</li>
  <li>Scan</li>
  </ul></li>
  <li>Kratki kominowe</li>
  <li>Wkłady kominowe</li>
  <li>Kominki gazowe</li>
  </ul>