-- 时间转任意格式DATE_FORMAT
-- #select DATE_FORMAT(NOW(),'%m-%d-%Y');
-- unix_timestamp 时间转时间戳
-- select unix_timestamp(now());  
-- from_unixtime 时间戳转时间
-- SELECT from_unixtime(created_time,'%m-%d-%Y') 

#按天统计
-- SELECT from_unixtime(created_time,'%m-%d-%Y') AS date, COUNT(*) AS num
-- FROM filter_ip
-- GROUP BY date
-- ORDER BY date;


#按小时统计
-- SELECT from_unixtime(created_time, '%Y-%m-%d %H:00:00') AS time, COUNT(*) AS num
-- FROM filter_ip
-- GROUP BY time
-- ORDER BY time;

#按分钟统计
-- SELECT DATE_FORMAT(from_unixtime(created_time), '%Y-%m-%d %H:%i:00') AS time, COUNT(*) AS num
-- FROM filter_ip 
-- GROUP BY time
-- ORDER BY time;

#按十分钟统计、按半小时统计只需要把10改为30

SELECT time, COUNT( * ) AS num 
FROM
    (
    SELECT 
        DATE_FORMAT(
            concat( date( from_unixtime(created_time) ), ' ', HOUR ( from_unixtime(created_time) ), ':', floor( MINUTE ( from_unixtime(created_time) ) / 10 ) * 10 ),
            '%Y-%m-%d %H:%i' 
        ) AS time 
    FROM filter_ip
    ) a 
GROUP BY DATE_FORMAT( time, '%Y-%m-%d %H:%i' ) 
ORDER BY time;

参考：https://blog.csdn.net/u010946448/article/details/83752984