title: Cannot remove replicated towns. Should it be a query issue?
body: <p>I have a problem with displaying the towns in select tag. They are displayed in this way: <a href="https://i.stack.imgur.com/pxIPY.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pxIPY.jpg" alt="enter image description here"></a></p>
  
  <p>As you can see, there are towns like <strong>Berlin</strong> which are duplicated. Also, I display them in dropdown list with the foolowing block of code:</p>
  
  <pre><code>&lt;select id="veneue_finder_city_select" name="city_id"&gt;
                                  &lt;option value=""&gt;Any&lt;/option&gt;
                                  &lt;?php
                                  if( !empty($state_id) ) {
  
                                      $states = array();
                                      $cities = $wpdb-&gt;get_results( "select ID, post_title from $wpdb-&gt;posts where post_type = 'place' and post_parent = $state_id", ARRAY_A );
  
                                      foreach( $cities as $city ):
                                      ?&gt;
                                          &lt;option value="&lt;?php echo $city['ID']; ?&gt;" &lt;?php selected($city['ID'], $city_id) ?&gt;&gt;&lt;?php echo $city['post_title']; ?&gt;&lt;/option&gt;
                                      &lt;?php endforeach;
                                  }?&gt;
                              &lt;/select&gt;
  </code></pre>
  
  <p>I've already tried to use <strong>Distinct</strong>  type in the query, but without success. Should it be something else ? This is my <strong>stade_id</strong></p>
  
  <pre><code>$state_id = isset( $_GET['state_id'] ) ? $_GET['state_id'] : '';
  </code></pre>