[mysql]랭크 select

mysql 에서 point, stage로 랭크 sql문

   SELECT point,stage,username
			CASE 
			WHEN @prev_value=point THEN @vRank 
			WHEN @prev_value := point THEN @vRank := @vRank + 1 
            WHEN @prev_value = point THEN @vRank := @vRank + 1 
			END AS rank 
			FROM drop_user as p, (SELECT @vRank := 0, @prev_value := 0) as r 
			ORDER BY point desc, stage desc limit 0, 20