SQLite query to find datetime difference between multiple rows - sql

Question

Here are my two tables' structures in SQLite
CREATE TABLE user
(
id integer PRIMARY KEY,
name TEXT
);
CREATE TABLE attendanceTable
(
id Integer,
mydate datetime,
startJob boolean
);
if startJob is 1 it implies that the employee is starting the job and if startJob is 0 it means employee is stopping the job.
attendanceTable is sorted by mydate column
I want output as worked hour by individual employees.
Input of query can be two different dates e.g. 2021-08-20 and 2021-08-22
From which I want to know "How much each person has worked?"
Output should be:
[id, name, userWorkedTime]
[1, Alice, 09:00]
[2, Bob, 07:00]
12:00 to 16:00 + 22:00 to 03:00 = 9 hours
13:00 to 17:00 + 12:00 to 15:00 = 7 hours
Input of query 2021-08-20 and 2021-08-21 - output should be:
[id, name, userWorkedTime]
[1, Alice, 09:00]
[2, Bob, 04:00]
12:00 to 16:00 + 22:00 to 03:00 = 9 hours
13:00 to 17:00 = 4 hours
It may possible that Alice starts her job at 11 PM and end her job at 3 AM on next day[So working hour would be 4 hours]

Answer 1

I believe that the following will accomplish the results you desire:-
WITH
/* The date selection parameters - change as necessary */
cte_selection(selection_start,selection_end) AS (SELECT '2020-08-20','2020-08-22'),
/* Extract data per shift - aka combine start and end
note that extract is 1 day befor and 1 day after actual selection criteria
as previous/subsequent days may be relevant
*/
cte_part1(userid,name,periodstart,periodend,duration) AS
(
SELECT
user.id,
name,
strftime('%s',mydate),
strftime('%s',
(
SELECT mydate
FROM attendancetable
WHERE id = at.id
AND NOT startjob
AND mydate > at.mydate
ORDER BY mydate ASC
LIMIT 1
)
) AS endjob,
(strftime('%s',
(
SELECT mydate
FROM attendancetable
WHERE id = at.id
AND NOT startjob
AND mydate > at.mydate
ORDER BY mydate ASC
LIMIT 1
)
) - strftime('%s',at.mydate)) AS duration
FROM attendancetable AS at
JOIN user ON at.id = user.id
WHERE startjob
AND mydate
BETWEEN date
(
(SELECT selection_start FROM cte_selection)
,'-1 day'
)
AND date
(
(SELECT selection_end FROM cte_selection)
,'+1 day'
)
),
/* split times if period crosses a day*/
cte_part2(userid,name,periodstart,startdate,periodend,enddate,duration,startday_duration,nextday_duration) AS
(
SELECT
userid,
name,
periodstart,
date(periodstart,'unixepoch') AS startdate,
periodend,
date(periodend,'unixepoch') AS enddate,
duration,
CASE
WHEN date(periodstart,'unixepoch') = date(periodend,'unixepoch') THEN duration
ELSE strftime('%s',date(periodstart,'unixepoch')||'24:00:00') - periodstart
END AS startday_duration,
CASE
WHEN date(periodstart,'unixepoch') = date(periodend,'unixepoch') THEN 0
ELSE periodend - strftime('%s',date(periodend,'unixepoch')||'00:00:00')
END AS nextday_duration
FROM cte_part1
),
/* generate new rows for following days */
cte_part3(userid,name,periodstart,startdate,periodend,enddate,duration,startday_duration,nextday_duration) AS
(
SELECT
userid,
name,
strftime('%s',date(periodend,'unixepoch')||'00:00:00'),
date(periodend,'unixepoch'),
periodend,
enddate,
nextday_duration,
nextday_duration,
0
FROM cte_part2
WHERE nextday_duration
),
/* combine both sets */
cte_part4 AS (SELECT * FROM cte_part2 UNION ALL SELECT * FROM cte_part3)
/* Group the final data */
SELECT *,time(sum(startday_duration),'unixepoch') AS time_worked
FROM cte_part4
WHERE startdate BETWEEN (SELECT selection_start FROM cte_selection) AND (SELECT selection_end FROM cte_selection) GROUP BY userid
;
e.g. :-
and :-
Note All results with the exception of the time_worked are arbitrary values from the underlying data. However, userid and name will be correct as they would be the same for each group. The other values will be a value from the group.
you can easily apply changes to the final query to include or exclude columns.
The full testing SQL being :-
DROP TABLE IF EXISTS user;
CREATE TABLE IF NOT EXISTS user (id integer PRIMARY KEY,name TEXT);
DROP TABLE IF EXISTS attendanceTable ;
CREATE TABLE attendanceTable(id Integer,mydate datetime,startJob boolean);
INSERT INTO user VALUES (1,'Alice'),(2,'Bob');
INSERT INTO attendanceTable VALUES
(1,'2020-08-20 12:00:00',1),
(2,'2020-08-20 13:00:00',1),
(1,'2020-08-20 16:00:00',0),
(2,'2020-08-20 17:00:00',0),
(1,'2020-08-20 22:00:00',1),
(1,'2020-08-21 03:00:00',0),
(2,'2020-08-22 12:00:00',1),
(2,'2020-08-22 15:00:00',0)
;
WITH
/* The date selection parameters - change as necessary */
cte_selection(selection_start,selection_end) AS (SELECT '2020-08-20','2020-08-22'),
/* Extract data per shift - aka combine start and end
note that extract is 1 day befor and 1 day after actual selection criteria
as previous/subsequent days may be relevant
*/
cte_part1(userid,name,periodstart,periodend,duration) AS
(
SELECT
user.id,
name,
strftime('%s',mydate),
strftime('%s',
(
SELECT mydate
FROM attendancetable
WHERE id = at.id
AND NOT startjob
AND mydate > at.mydate
ORDER BY mydate ASC
LIMIT 1
)
) AS endjob,
(strftime('%s',
(
SELECT mydate
FROM attendancetable
WHERE id = at.id
AND NOT startjob
AND mydate > at.mydate
ORDER BY mydate ASC
LIMIT 1
)
) - strftime('%s',at.mydate)) AS duration
FROM attendancetable AS at
JOIN user ON at.id = user.id
WHERE startjob
AND mydate
BETWEEN date
(
(SELECT selection_start FROM cte_selection)
,'-1 day'
)
AND date
(
(SELECT selection_end FROM cte_selection)
,'+1 day'
)
),
/* split times if period crosses a day*/
cte_part2(userid,name,periodstart,startdate,periodend,enddate,duration,startday_duration,nextday_duration) AS
(
SELECT
userid,
name,
periodstart,
date(periodstart,'unixepoch') AS startdate,
periodend,
date(periodend,'unixepoch') AS enddate,
duration,
CASE
WHEN date(periodstart,'unixepoch') = date(periodend,'unixepoch') THEN duration
ELSE strftime('%s',date(periodstart,'unixepoch')||'24:00:00') - periodstart
END AS startday_duration,
CASE
WHEN date(periodstart,'unixepoch') = date(periodend,'unixepoch') THEN 0
ELSE periodend - strftime('%s',date(periodend,'unixepoch')||'00:00:00')
END AS nextday_duration
FROM cte_part1
),
/* generate new rows for following days */
cte_part3(userid,name,periodstart,startdate,periodend,enddate,duration,startday_duration,nextday_duration) AS
(
SELECT
userid,
name,
strftime('%s',date(periodend,'unixepoch')||'00:00:00'),
date(periodend,'unixepoch'),
periodend,
enddate,
nextday_duration,
nextday_duration,
0
FROM cte_part2
WHERE nextday_duration
),
/* combine both sets */
cte_part4 AS (SELECT * FROM cte_part2 UNION ALL SELECT * FROM cte_part3)
/* Group the final data */
SELECT *,time(sum(startday_duration),'unixepoch') AS time_worked
FROM cte_part4
WHERE startdate BETWEEN (SELECT selection_start FROM cte_selection) AND (SELECT selection_end FROM cte_selection) GROUP BY userid
;
DROP TABLE IF EXISTS user;
DROP TABLE IF EXISTS attendanceTable ;