Calculate the total time spent in a week - sql

Question

I want to calculate the total time spent in a week (the start of the week will be from a given date).
Here the given date is 2020-06-23 15:30:00. And the next week will start from 7 days after.
The duration of the activity will be calculated by the time gap between two rows for the same id if only the second is less than an hour after the first.
select t.UserName,
1 + datediff(second, '2020-06-23 15:30:00', CompletedOn) / (24 * 60 * 60 * 7) as week_num,
sum(datediff(minute, CompletedOn, next_ts)) as duration_minutes
from (select t.*,
lead(CompletedOn) over (partition by UserName order by CompletedOn) as next_ts
from #Results t
where t.CompletedOn >= '2020-06-23 15:30:00'
) t
where datediff(minute, CompletedOn, next_ts) < 60 and CompletedOn >='2020-06-23 15:30:00' and t.UserName = 'John B'
group by t.UserName, datediff(second, '2020-06-23 15:30:00', CompletedOn) / (24 * 60 * 60 * 7)
order by t.UserName, week_num;
The above query doesn't consider displaying the week_num if there is no entry for the date in the week, so it display the result as:
UserName | week_num | duration_minutes
---------------|----------|------------------
John B | 1 | 38
John B | 2 | 10
John B | 3 | 0
John B | 5 | 0
However, I wanted the output as all the week number that falls up to the last date in the record.
UserName | week_num | duration_minutes
---------------|----------|------------------
John B | 1 | 38
John B | 2 | 10
John B | 3 | 0
John B | 4 | 0
John B | 5 | 0
Some of the sample data:
IF OBJECT_ID('tempdb..#Results') IS NOT NULL
Truncate TABLE #Results
else
CREATE TABLE #Results
(
UserName varchar(20) not null,
CompletedOn datetime not null
)
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-23T15:30:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-23T15:31:00'
--1 min
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-30T12:57:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-30T13:06:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-30T13:34:00'
--37 min
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-30 15:31:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-30 15:33:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-06-30 15:41:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-06 08:41:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-07 14:29:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-09 15:22:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-09 16:23:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-21 15:34:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-21 17:00:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-09 15:22:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-09 16:23:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-21 15:34:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-21 17:00:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-21 17:00:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-23 06:34:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-23 08:28:00'
INSERT INTO #Results (UserName, CompletedOn)
SELECT 'John B', '2020-07-23 08:28:00'
Db Fiddle

Answer 1

Consider joining to a recursive CTE that generates pair matches of UserName and all subsequent week_num to a defined end point. Below uses 10 but can extend to say 52.
WITH pairs AS (
SELECT DISTINCT UserName, 1 AS week_num
FROM #Results
UNION ALL
SELECT UserName, week_num + 1
FROM pairs
WHERE week_num < 10 -- ADJUST ## AS NEEDED
), sub AS (
SELECT t.UserName
, t.CompletedOn
, LEAD(CompletedOn) OVER (PARTITION BY t.UserName ORDER BY t.CompletedOn) as next_ts
FROM #Results t
WHERE t.CompletedOn >= '2020-06-23 15:30:00'
), main AS (
SELECT sub.UserName
, 1 + DATEDIFF(SECOND, '2020-06-23 15:30:00', sub.CompletedOn) / (24 * 60 * 60 * 7) AS week_num
, SUM(DATEDIFF(MINUTE, sub.CompletedOn, sub.next_ts)) AS duration_minutes
FROM sub
WHERE DATEDIFF(MINUTE, sub.CompletedOn, sub.next_ts) < 60
AND sub.CompletedOn >='2020-06-23 15:30:00'
AND sub.UserName = 'John B'
GROUP BY sub.UserName
, DATEDIFF(SECOND, '2020-06-23 15:30:00', sub.CompletedOn) / (24 * 60 * 60 * 7)
)
SELECT pairs.UserName
, pairs.week_num
, ISNULL(main.duration_minutes, 0) AS duration_minutes
FROM pairs
LEFT JOIN main
ON pairs.UserName = main.UserName
AND pairs.week_num = main.week_num
OPTION (MAXRECURSION 0);
Online Demo
| | UserName | week_num | duration_minutes |
|----|----------|----------|------------------|
| 1 | John B | 1 | 38 |
| 2 | John B | 2 | 10 |
| 3 | John B | 3 | 0 |
| 4 | John B | 4 | 0 |
| 5 | John B | 5 | 0 |
| 6 | John B | 6 | 0 |
| 7 | John B | 7 | 0 |
| 8 | John B | 8 | 0 |
| 9 | John B | 9 | 0 |
| 10 | John B | 10 | 0 |