Question

我想根据日期列找到给定值的最长序列，例如给定表格：

+-------+-------------------+
|value  |timestamp          |
+-------+-------------------+
|1      |2021-02-20 13:31:21|
|0      |2021-02-20 13:31:58|
|1      |2021-02-20 13:32:00|
|1      |2021-02-20 13:33:24|
|1      |2021-02-20 13:34:12|
|0      |2021-02-20 13:36:51|

对于值“1”，最长的序列是 2 分 12 秒长，如何做到这一点？

希望有人能帮忙！谢谢！

Answer 1

您可以通过累计计算 0 值的数量来分配一个组。然后只需聚合即可查看所有组：

select min(timestamp), max(timestamp)
from (select t.*,
             sum(value = 0) over (order by timestamp) as grp
      from t
     ) t
where value = 1
group by grp;

计算差值并取最长周期：

select min(timestamp), max(timestamp),
       second_to_time(to_seconds(max(timestamp)) - to_seconds(min(timetamp)))
from (select t.*,
             sum(value = 0) over (order by timestamp) as grp
      from t
     ) t
where value = 1
group by grp
order by to_seconds(max(timestamp)) - to_seconds(min(timetamp)) desc
limit 1;

MySQL查询以根据日期查找最长的值序列

1 个答案: