MySQL calculate duration by date till end of date using lead function - mysql

Question

I have a table that stores the records for users' different sessions(subscribe, unsubscribe, away, online). I am able to calculate the time duration for each session using the following given query.
There is a scenario that supposes a user starts his online session on "15-May-2022 at 11:00:00 PM", after that on the next day he set himself away on "16-May-2022 at 02:00:00 AM"
Total online is 3 Hours which I am getting as the last row on the date 15-May-2022.
But I need like this
On 15-May till "15-May-2022 23:59:59" it was online for 1 Hour and on 16-May from "16-May-2022 00:00:00 to 16-May-2022 at 02:00:00 AM", it was online for 2 Hours. So in response, it should return 1 hour for 15-May and 2 hours for 16-May, not a total of 3 hours on 15-May.
I am using the lead function to get the duration from the created_at column, is there any way in which I can restrict the lead function to calculate duration till the next created_at till 23:59:59.
Here is my working query. I am using the latest MySQL(8) version.
select `id`, `user_id`, `status`, `created_at`,
SEC_TO_TIME(TIMESTAMPDIFF(SECOND, created_at,
LEAD(created_at) OVER (PARTITION BY user_id ORDER BY created_at))) as duration,
date(created_at) as date from `user_websocket_events` as `all_status`
where created_at between '2022-05-15 00:00:00' and '2022-05-16 23:59:59' and `status` is not null
and user_id in (69) order by `id` asc;
Here is some sample data.
INSERT INTO user_websocket_events (id, user_id, event, status, extra_attributes, created_at, updated_at) VALUES (10816, 69, 'subscribe', 'online', null, '2022-05-15 12:57:31', '2022-05-14 10:57:37');
INSERT INTO user_websocket_events (id, user_id, event, status, extra_attributes, created_at, updated_at) VALUES (10817, 69, 'away', 'away', null, '2022-05-15 20:57:31', '2022-05-14 10:57:37');
INSERT INTO user_websocket_events (id, user_id, event, status, extra_attributes, created_at, updated_at) VALUES (10818, 69, 'online', 'online', null, '2022-05-15 22:57:31', '2022-05-14 10:57:37');
INSERT INTO user_websocket_events (id, user_id, event, status, extra_attributes, created_at, updated_at) VALUES (10819, 69, 'away', 'away', null, '2022-05-16 02:57:31', '2022-05-14 10:57:37');
INSERT INTO user_websocket_events (id, user_id, event, status, extra_attributes, created_at, updated_at) VALUES (10820, 69, 'unsubscribe', 'unsubscribe', null, '2022-05-16 03:57:31', '2022-05-14 10:57:37');

Answer 1

Using an on-the-fly calendar table to split a session by days
with recursive calendar as (
select timestamp('2022-05-01 00:00') start_time, timestamp('2022-05-01 23:59:59') end_time, 1 id
union all
select start_time + interval 1 day, end_time + interval 1 day, id+1
from calendar
where id < 100
)
select e.id, e.status, date(greatest(c.start_time, e.created_at)) date,
greatest(c.start_time, e.created_at) as created_at,
least(c.end_time, e.ended_at) as ended_at
from (
select `id`, `user_id`, `status`, `created_at`,
-- a session end is restricted to the end of the requierd interval
LEAD(created_at, 1, '2022-05-16 23:59:59') OVER (PARTITION BY user_id ORDER BY created_at) as ended_at
from `user_websocket_events`
where
-- only sessions started within the requierd interval
created_at between '2022-05-15 00:00:00' and '2022-05-16 23:59:59' and `status` is not null
and user_id in (69)
) e
join calendar c on c.start_time < e.ended_at and e.created_at < c.end_time
order by id;
db<>fiddle

Answer 2

You need to handle it using CASE statement.
Now instead of the actual created_at and LEAD(created_at), we need something like below.
First Case:
If the created_at and LEAD(created_at) falls on different date, then consider date(created_at) + '23:59:59' else consider created_at as ENDTIME.
CASE
WHEN Date(lead_created_at)=Date(created_at) THEN lead_created_at
ELSE Addtime(Timestamp(Date(created_at)),'23:59:59')
END
Second Case:
If the created_at and LAG(created_at) falls on different date, then consider date(created_at) + '00:00:00' else consider created_at as STARTTIME.
CASE
WHEN Date(lag_created_at)=Date(created_at) THEN created_at
ELSE Timestamp(Date(created_at))
END
Finally, the query can be written as below to get the desired output.
SELECT `id`,
`user_id`,
`status`,
`created_at`,
CASE
WHEN Date(lag_created_at)=Date(created_at) THEN created_at
ELSE Timestamp(Date(created_at))
end new_starttime,
CASE
WHEN Date(lead_created_at)=Date(created_at) THEN lead_created_at
WHEN lead_created_at is null then null
ELSE Addtime(Timestamp(Date(created_at)),'23:59:59')
end AS new_endtime,
Sec_to_time(Timestampdiff(second,
CASE
WHEN Date(lag_created_at)=Date(created_at) THEN created_at
ELSE Timestamp(Date(created_at))
end,
CASE
WHEN Date(lead_created_at)=Date(created_at) THEN lead_created_at
WHEN lead_created_at is null then null
ELSE Addtime(Timestamp(Date(created_at)),'23:59:59')
end )) AS duration,
date
FROM (
SELECT `id`,
`user_id`,
`status`,
`created_at`,
(Lead(created_at) over (partition BY user_id ORDER BY created_at)) AS lead_created_at,
coalesce(lag(created_at) over (partition BY user_id ORDER BY created_at),created_at) AS lag_created_at,
date(created_at) AS date
FROM `user_websocket_events` AS `all_status`
WHERE created_at BETWEEN '2022-05-15 00:00:00' AND '2022-05-16 23:59:59'
AND `status` IS NOT NULL
AND user_id IN (69) )tmp
ORDER BY `id` ASC;
Resultset:
id
user_id
status
created_at
new_starttime
new_endtime
duration
date
10816
69
online
2022-05-15 12:57:31
2022-05-15 12:57:31
2022-05-15 20:57:31
08:00:00
2022-05-15
10817
69
away
2022-05-15 20:57:31
2022-05-15 20:57:31
2022-05-15 22:57:31
02:00:00
2022-05-15
10818
69
online
2022-05-15 22:57:31
2022-05-15 22:57:31
2022-05-15 23:59:59
01:02:28
2022-05-15
10819
69
away
2022-05-16 02:57:31
2022-05-16 00:00:00
2022-05-16 03:57:31
03:57:31
2022-05-16
10820
69
unsubscribe
2022-05-16 03:57:31
2022-05-16 03:57:31
null
null
2022-05-16
Note: The query will not handle the scenario where sessions last more than 48 hour.
DB Fiddle: Try it here