How can I create a "start" "end" time table from a timestamp list - sql

Question

I am trying to create a view that displays the time of employee stamps.
This is what the table looks like now:
Person
Person_Number
Date
Stamp_number
Time_Stamp
Paul
1
22-10-24
1
8:00
Paul
1
22-10-24
2
10:00
Paul
1
22-10-24
3
10:30
Paul
1
22-10-24
4
12:00
Jimmy
2
22-10-23
1
9:00
Jimmy
2
22-10-23
2
11:00
Jimmy
2
22-10-23
3
12:00
And I would like it to look like this using only a select query
Person
Person_Number
Date
Start
End
Duration
Paul
1
22-10-24
8:00
10:00
2:00
Paul
1
22-10-24
10:30
12:00
1:30
Jimmy
2
22-10-23
9:00
11:00
2:00
Jimmy
1
22-10-23
12:00
null
null
Is it possible ?

Answer 1

We can use conditional aggregation along with a ROW_NUMBER trick:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY Person_Number, Date
ORDER BY Stamp_number) - 1 rn
FROM yourTable
)
SELECT Person, Person_Number, Date,
MAX(CASE WHEN rn % 2 = 0 THEN Time_Stamp END) AS [Start],
MAX(CASE WHEN rn % 2 = 1 THEN Time_Stamp END) AS [End],
DATEDIFF(MINUTE,
MAX(CASE WHEN rn % 2 = 0 THEN Time_Stamp END),
MAX(CASE WHEN rn % 2 = 1 THEN Time_Stamp END)) AS Duration
FROM cte
GROUP BY Person, Person_Number, Date, rn / 2
ORDER BY 2, 4;
Here is a working demo.

Answer 2

Try the following:
SELECT Person, Person_Number, Date, [Start], [End],
CONVERT(TIME(0), CONVERT(DATETIME, [End]) - CONVERT(DATETIME, [Start])) AS Duration
FROM
(
SELECT Person, Person_Number, Date, MIN(Time_Stamp) AS [Start],
CASE
WHEN MAX(Time_Stamp) <> MIN(Time_Stamp)
THEN MAX(Time_Stamp)
END AS [End] /* To select End as null when there is no End for a Start */
FROM table_name
GROUP BY Person, Person_Number, Date, (Stamp_number+1)/2
) T
ORDER BY Person_Number, Date, [Start]
See a demo.