MySQL中统计一天之内每个时间段内的数据，很急

时间段统计，可以采用 hour(subscribe_time) 取出小时然后分层。思路：

select

uid

,CASE WHEN HOUR(subscribe_time) BETWEEN 0 AND 1 THEN '00:00:00'

WHEN HOUR(subscribe_time) BETWEEN 2 AND 3 THEN '02:00:00'

...

ELSE '23:00:00' END -- 生成时间分层部分，insert前外层sql加上日期后作为唯一的时间值

,COUNT(*)

FROM yht_fans WHERE subscribe_time>=UNIX_TIMESTAMP(CURDATE()) and subscribe_time<=UNIX_TIMESTAMP(CURDATE())+86400

GROUP BY 1,2

SELECT * FROM NODE

WHERE PREV_NODE_ID NOT IN (SELECT DISTINCT NODE_ID FROM NODE)

AND PRNT_NODE_ID NOT IN (SELECT DISTINCT NODE_ID FROM NODE)

将 SELECT * 换成 DELETE 即可删除了

那就将语句改成下面这样

DELETE FROM NODE A

WHERE A.PREV_NODE_ID NOT IN (SELECT DISTINCT B.NODE_ID FROM NODE B WHERE B.ID = A.ID)

AND A.PRNT_NODE_ID NOT IN (SELECT DISTINCT B.NODE_ID FROM NODE B WHERE B.ID = A.ID)

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