Mysql 不重叠的时间差之和

我有一个像这样的MySql表：

ID  | activity        | start               | end
372 | Machine Running | 2018-01-30 21:19:42 | 2018-01-30 21:52:41
373 | Order Active    | 2018-01-30 21:19:42 | 2018-01-30 21:45:02
374 | Operator Active | 2018-01-30 21:19:42 | 2018-01-30 21:52:41
375 | Reporting Active| 2018-01-30 21:19:48 | 2018-01-30 21:20:06
376 | Admin Active    | 2018-01-30 21:20:09 | 2018-01-30 21:52:41
378 | Order Active    | 2018-01-30 21:49:23 | 2018-01-30 21:52:41
982 | Machine Running | 2018-02-20 15:01:55 | 2018-02-20 15:01:55
983 | Order Active    | 2018-02-20 15:01:55 | 2018-02-20 15:01:55
984 | Operator Active | 2018-02-20 15:01:55 | 2018-02-20 15:01:55
986 | Machine Running | 2018-02-20 15:02:30 | 2018-02-20 15:02:30
987 | Order Active    | 2018-02-20 15:02:30 | 2018-02-20 15:02:30
988 | Operator Active | 2018-02-20 15:02:30 | 2018-02-20 15:02:30

我必须找出机器运行的时间和什么都不做的时间。 因此，机器运行的时间很容易。这只是开始和结束时间的时间差

但是对于表中运行的每台机器，我需要一行“机器什么也不做”。在我看来，我必须从机器不重叠运行的总时间中减去属于一台机器运行的所有活动的时间差，但我不知道如何做到这一点

对于上面的表，我需要这样的输出

start      | activity        | seconds
2018-07-02 | Machine Running | xx 
2018-07-02 | Doing nothing   | xx
2018-06-27 | Machine Running | xx
2018-06-27 | Doing nothing   | xx

SELECT t1.start, UNIX_TIMESTAMP(t1.end) - UNIX_TIMESTAMP(t1.start) AS total_time, SUM(
GREATEST(0,UNIX_TIMESTAMP(t1.end) - UNIX_TIMESTAMP(t1.start)
  - GREATEST(0,UNIX_TIMESTAMP(t1.end) - UNIX_TIMESTAMP(t2.end)) 
  - GREATEST(0,UNIX_TIMESTAMP(t2.start) - UNIX_TIMESTAMP(t1.start)))
) AS do_nothing /* duration in seconds */
FROM tbl AS t1
LEFT JOIN tbl AS t2 ON (t2.start BETWEEN t1.start AND t1.end)
  OR (t2.end BETWEEN t1.start AND t1.end)
WHERE t1.activity = 'Machine Running' AND t2.activity = 'Operator Active'
GROUP BY t1.start

---

对于

类型机器运行的每个间隔

，您需要找到

类型操作员活动的所有重叠间隔

——我指的是

机器运行

和

操作员活动

之间的重叠。然后，您必须从运行的相应

机器

中减去每个

操作员活动

的重叠。最终结果将是

无所事事的持续时间

为此，您需要一个公式来计算两个时间间隔之间的重叠

GREATEST(0,interval_1_end - interval_1_start - GREATEST(0,interval_1_end - interval_2_end) - GREATEST(0,interval_2_start - interval_1_start))

间隔必须表示为UNIX时间戳

然后像这样

start      | activity        | seconds
2018-07-02 | Machine Running | xx 
2018-07-02 | Doing nothing   | xx
2018-06-27 | Machine Running | xx
2018-06-27 | Doing nothing   | xx

SELECT t1.start, UNIX_TIMESTAMP(t1.end) - UNIX_TIMESTAMP(t1.start) AS total_time, SUM(
GREATEST(0,UNIX_TIMESTAMP(t1.end) - UNIX_TIMESTAMP(t1.start)
  - GREATEST(0,UNIX_TIMESTAMP(t1.end) - UNIX_TIMESTAMP(t2.end)) 
  - GREATEST(0,UNIX_TIMESTAMP(t2.start) - UNIX_TIMESTAMP(t1.start)))
) AS do_nothing /* duration in seconds */
FROM tbl AS t1
LEFT JOIN tbl AS t2 ON (t2.start BETWEEN t1.start AND t1.end)
  OR (t2.end BETWEEN t1.start AND t1.end)
WHERE t1.activity = 'Machine Running' AND t2.activity = 'Operator Active'
GROUP BY t1.start

那么什么也不做就是一个机器运行行的结束时间和下一个机器运行行的开始时间之间的差异？您使用的是哪个版本的mysql？无所事事是指从机器运行的开始到结束都没有发生任何事情。下一次机器启动没什么可干的。仅在机器运行的开始和结束时间内发生活动@P.Salmon