我需要查找并合并表中按时间相关的记录。该表记录了网站中的用户事件(事件开始和事件结束时间)。
我正在尝试将同一用户在一小时内进行的其他事件合并为一条记录。因此,如果一条记录的开始时间是同一用户上一次事件结束后 55 分钟,我会将其合并以形成一条记录。
我尝试了各种自连接来实现此目的,但结果从来都不是完美的。
分两步,我尝试了这个:
首先更新updated_at(事件结束),以便在一小时内的所有记录都具有共同的updated_at时间戳,这是该组中最新的。
删除组中所有较晚的记录,以便仅保留最早的记录,现在具有最早的created_at和最新的updated_at
-- 首先为一个用户的所有事件设置一个共同的结束时间 (updated_at),时间间隔不超过一个小时
UPDATE users_activity
SET updated_at = (SELECT a.LatestEnd FROM (SELECT
UA1.id,
MAX(UA2.updated_at) AS LatestEnd
FROM users_activity UA1, users_activity UA2
WHERE
UA1.id <> UA2.id
AND UA1.user_id = UA2.user_id
AND UA1.created_at > DATE_SUB(UA2.updated_at,INTERVAL 1 HOUR)
AND UA1.created_at < UA2.updated_at
) a)
WHERE
users_activity.id IN (SELECT b.id FROM (SELECT
UA1.id
FROM users_activity UA1, users_activity UA2
WHERE
UA1.id <> UA2.id
AND UA1.user_id = UA2.user_id
AND UA1.created_at > DATE_SUB(UA2.updated_at,INTERVAL 1 HOUR)
AND UA1.created_at < UA2.updated_at
) b);
-- next delete all the later records in the group, leaving only the earliest
DELETE FROM users_activity
WHERE
users_activity.id IN (SELECT * FROM (SELECT d.id FROM users_activity d
INNER JOIN
(SELECT
COUNT(CONCAT(user_id,'_',updated_at)) AS Duplicates,
CONCAT(user_id,'_',updated_at) AS UserVisitEnd,
id,
user_id,
MAX(created_at) AS LatestStart
FROM users_activity
GROUP BY UserVisitEnd
HAVING Duplicates > 1) a on a.LatestStart = d.created_at AND a.user_id = d.user_id) as AllDupes);
如果数据是这样的:
|id |user_id|created_at |updated_at
|5788|1222 |2019-06-06 08:55:28|2019-06-06 09:30:41
|5787|3555 |2019-06-06 08:40:04|2019-06-06 11:07:21
|5786|1222 |2019-06-06 07:11:03|2019-06-06 08:01:29
|5785|7999 |2019-06-05 18:11:03|2019-05-01 18:17:44
|5784|3555 |2019-06-04 16:53:32|2019-06-04 16:58:19
|5783|9222 |2019-04-01 15:21:32|2019-04-01 16:53:32
|5782|1222 |2019-03-29 14:02:09|2019-03-29 15:51:07
|5774|1222 |2019-03-29 13:38:43|2019-03-29 13:50:43
|5773|7999 |2018-09-23 17:38:35|2018-09-23 17:40:35
我应该得到这个结果:
|id |user_id|created_at |updated_at
|5787|3555 |2019-06-06 08:40:04|2019-06-06 11:07:21
|5786|1222 |2019-06-06 07:11:03|2019-06-06 09:30:41
|5785|7999 |2019-06-05 18:11:03|2019-05-01 18:17:44
|5784|3555 |2019-06-04 16:53:32|2019-06-04 16:58:19
|5783|9222 |2019-04-01 15:21:32|2019-04-01 16:53:32
|5774|1222 |2019-03-29 13:38:43|2019-03-29 15:51:07
|5773|7999 |2018-09-23 17:38:35|2018-09-23 17:40:35
新信息。此查询将得到包含我需要的信息的结果:要更新和合并的 session ID。但是,当每行的更新可能会更改其他行所需的更新时,如何进行批量更新?
SELECT b.id, b.user_id, b.created_at, b.updated_at, b.UpdatedAtOfSessionToMerge, b.IDofSessionToMerge FROM (SELECT
UA1.id,
UA1.user_id,
UA1.created_at,
UA1.updated_at,
UA2.updated_at AS UpdatedAtOfSessionToMerge,
UA2.id AS IDofSessionToMerge
FROM users_activity UA1, users_activity UA2
WHERE
UA1.id <> UA2.id
AND UA1.user_id = UA2.user_id
AND UA1.created_at > DATE_SUB(UA2.updated_at,INTERVAL 1 HOUR)
AND UA1.updated_at < UA2.updated_at
AND UA1.created_at < UA2.updated_at
) b order by b.user_id;
最佳答案
SELECT min(ID) as ID, User_ID, Min(Created_At) Created_At, Max(Updated_At) as Updated_At
FROM Table
GROUP BY User_ID, DATE_FORMAT(Created_At, "%Y%m%d%H");
会很接近,但我不确定我是否按照您想要的方式处理“小时”汇总。
关于mysql - 哪种连接可以合并单个 SQL 表中的记录?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56482183/