code: public function purgeSearchIndex(Contao\DataContainer $dc)
  	{
  		if (!$dc->id)
  		{
  			return;
  		}
  
  		$objResult = $this->Database->prepare("SELECT id FROM tl_search WHERE pid=?")
  									->execute($dc->id);
  
  		while ($objResult->next())
  		{
  			$this->Database->prepare("DELETE FROM tl_search WHERE id=?")
  						   ->execute($objResult->id);
  
  			$this->Database->prepare("DELETE FROM tl_search_index WHERE pid=?")
  						   ->execute($objResult->id);
  		}
  	}
docs: Purge the search index if a page is being deleted
  
  @param Contao\DataContainer $dc