code: public function move()
  	{
  		// Proceed only if all mandatory variables are set
  		if ($this->intId && Input::get('sid') && (!$GLOBALS['TL_DCA'][$this->strTable]['list']['sorting']['root'] || !\in_array($this->intId, $this->root)))
  		{
  			$objRow = $this->Database->prepare("SELECT * FROM " . $this->strTable . " WHERE id=? OR id=?")
  									 ->limit(2)
  									 ->execute($this->intId, Input::get('sid'));
  
  			$row = $objRow->fetchAllAssoc();
  
  			if ($row[0]['pid'] == $row[1]['pid'])
  			{
  				$this->Database->prepare("UPDATE " . $this->strTable . " SET sorting=? WHERE id=?")
  							   ->execute($row[0]['sorting'], $row[1]['id']);
  
  				$this->Database->prepare("UPDATE " . $this->strTable . " SET sorting=? WHERE id=?")
  							   ->execute($row[1]['sorting'], $row[0]['id']);
  
  				// Invalidate cache tags
  				$this->invalidateCacheTags($this);
  			}
  		}
  
  		$this->redirect($this->getReferer());
  	}
docs: Change the order of two neighbour database records