SQL: usage time of item between dates combining two tables - sql

Question

Trying to create query that will give me usage time of each car part between dates when that part is used. Etc. let say part id 1 is installed on 2018-03-01 and on 2018-04-01 runs for 50min and then on 2018-05-10 runs 30min total usage of this part shoud be 1:20min as result.
These are examples of my tables.
Table1
| id | part_id | car_id | part_date |
|----|-------- |--------|------------|
| 1 | 1 | 3 | 2018-03-01 |
| 2 | 1 | 1 | 2018-03-28 |
| 3 | 1 | 3 | 2018-05-10 |
Table2
| id | car_id | run_date | puton_time | putoff_time |
|----|--------|------------|---------------------|---------------------|
| 1 | 3 | 2018-04-01 | 2018-04-01 12:00:00 | 2018-04-01 12:50:00 |
| 2 | 2 | 2018-04-10 | 2018-04-10 15:10:00 | 2018-04-10 15:20:00 |
| 3 | 3 | 2018-05-10 | 2018-05-10 10:00:00 | 2018-05-10 10:30:00 |
| 4 | 1 | 2018-05-11 | 2018-05-11 12:00:00 | 2018-04-01 12:50:00 |
Table1 contains dates when each part is installed, table2 contains usage time of each part and they are joined on car_id, I have try to write query but it does not work well if somebody can figure out my mistake in this query that would be healpful.
My SQL query
SELECT SEC_TO_TIME(SUM(TIME_TO_SEC(TIMEDIFF(t1.puton_time, t1.putoff_time)))) AS total_time
FROM table2 t1
LEFT JOIN table1 t2 ON t1.car_id=t2.car_id
WHERE t2.id=1 AND t1.run_date BETWEEN t2.datum AND
(SELECT COALESCE(MIN(datum), '2100-01-01') AS NextDate FROM table1 WHERE
id=1 AND t2.part_date > part_date);
Expected result
| part_id | total_time |
|---------|------------|
| 1 | 1:20:00 |
Hope that this problem make sence because in my search I found nothing like this, so I need help.
Solution, thanks to Kota Mori
SELECT t1.id, SEC_TO_TIME(SUM(TIME_TO_SEC(TIMEDIFF(t2.puton_time, t2.putoff_time)))) AS total_time
FROM table1 t1
LEFT JOIN table2 t2 ON t1.car_id = t2.car_id
AND t1.part_date >= t2.run_date
GROUP BY t1.id

Answer 1

You first need to join the two tables by the car_id and also a condition that part_date should be no greater than run_date.
Then compute the total minutes for each part_id separately.
The following is a query example for SQLite (The only SQL engine that I have access to right now).
Since SQLite does not have datetime type, I convert strings into unix timestamp by strftime function. This part should be changed in accordance with the SQL engine you are using. Apart from that, this is fairly a standard sql and mostly valid for other SQL dialect.
SELECT
t1.id,
sum(
cast(strftime('%s', t2.putoff_time) as integer) -
cast(strftime('%s', t2.puton_time) as integer)
) / 60 AS total_minutes
FROM
table1 t1
LEFT JOIN
table2 t2
ON
t1.car_id = t2.car_id
AND t1.part_date <= t2.run_date
GROUP BY
t1.id
The result is something like the below. Note that ID 1 gets 80 minutes (1:20) as expected.
id total_minutes
0 1 80
1 2 80
2 3 30