nice way to do rankings

rank-calculations.php

<?php
/**
	 * get leaderboard data
	 *
	 * @param int $start starting position
	 *
	 * @return array
	 */
	public function leaderboard($start)
	{
		// set rank counting
		$this->db->query("SELECT {$start} INTO @rank;");
		// get resuluts

		$result = $this->db->select('id, @rank:=@rank+1 AS rank, name, score, city', FALSE)->limit(5, $start)->where('score', '>0')->order_by('score', 'DESC')->get('teams')->result_array();

		// set total ?
		$this->total = $this->db->count_all_results('teams');

		return $result;

	}