MySQLで5分毎、10分毎の集計

5分ごと

select from_unixtime(round(unix_timestamp(created_at) div (5 * 60)) * (5 * 60)) as timekey from waitings group by timekey;

10分ごと

select from_unixtime(round(unix_timestamp(created_at) div (10 * 60)) * (10 * 60)) as timekey from table group by timekey;