从日期时间开始的连续条纹和当前条纹的最大值

Question

我具有特定用户的以下数据-表温度-

time_stamp
2015-07-19 10:52:00
2015-07-18 10:49:00
2015-07-12 10:43:00
2015-06-08 12:32:00
2015-06-07 11:33:00
2015-06-06 10:05:00
2015-06-05 04:17:00
2015-04-14 04:11:00
2014-04-02 23:19:00

因此查询的输出应为-Maximum streak = 4, Current streak = 2

由于这些，最大条纹数= 4-

2015-06-08 12:32:00
2015-06-07 11:33:00
2015-06-06 10:05:00
2015-06-05 04:17:00

由于这些原因，当前连胜为2（假设今天的日期为2015-07-19）-

2015-07-19 10:52:00
2015-07-18 10:49:00

编辑：我想要一个用于MySQL的简单SQL查询

Answer 1

使用间隙和孤岛查询的一般方法是在数据中的行级别和在完整日期列表中的行标记每行。集群将具有相同的差异。

注意：我不知道此查询是否有效。我不记得MySQL是否允许标量子查询。我没有在MySQL中查找计算天间隔的方法。

select user_id, max(time_stamp), count(*)
from (
    select
        t.user_id, t.time_stamp,
        (
            select count(*)
            from T as t2
            where t2.user_id = t.user_id and t2.time_stamp <= t.time_stamp
        ) as rnk,
        number of days from t.time_stamp to current_date as days
    from T as t

) as data
group by usr_id, days - rnk

Answer 2

对于MAX streak(streak)，您可以使用此选项，我使用相同的查询来计算最大条纹。这可能对您有帮助

SELECT *
FROM (
   SELECT t.*, IF(@prev + INTERVAL 1 DAY = t.d, @c := @c + 1, @c := 1) AS streak, @prev := t.d
   FROM (
       SELECT date AS d, COUNT(*) AS n
       FROM table_name
       group by date

   ) AS t
   INNER JOIN (SELECT @prev := NULL, @c := 1) AS vars
) AS t
ORDER BY streak DESC LIMIT 1;