[Solved] Calculate time diffrence in SQL with shifts

by


Use a recursive sub-query factoring clause to generate each day within your time ranges and then correlate that with your shifts to restrict the time for each day to be within the shift hours and then aggregate to get the total:

Oracle 18 Setup:

CREATE TABLE times ( start_date, End_Date ) AS
SELECT DATE '2017-02-21' + INTERVAL '07:52:32' HOUR TO SECOND,
       DATE '2017-02-22' + INTERVAL '09:56:32' HOUR TO SECOND
FROM   DUAL
UNION ALL
SELECT DATE '2017-02-21' + INTERVAL '09:52:32' HOUR TO SECOND,
       DATE '2017-02-23' + INTERVAL '17:52:32' HOUR TO SECOND
FROM   DUAL;

CREATE TABLE weekly_shifts ( shift_day, Start_Time, End_Time ) AS
SELECT 'MON', INTERVAL '09:00' HOUR TO MINUTE, INTERVAL '18:00' HOUR TO MINUTE FROM DUAL UNION ALL
SELECT 'TUE', INTERVAL '10:00' HOUR TO MINUTE, INTERVAL '19:00' HOUR TO MINUTE FROM DUAL UNION ALL
SELECT 'WED', INTERVAL '09:00' HOUR TO MINUTE, INTERVAL '18:00' HOUR TO MINUTE FROM DUAL UNION ALL
SELECT 'THU', INTERVAL '10:00' HOUR TO MINUTE, INTERVAL '19:00' HOUR TO MINUTE FROM DUAL UNION ALL
SELECT 'FRI', INTERVAL '09:00' HOUR TO MINUTE, INTERVAL '18:00' HOUR TO MINUTE FROM DUAL;

Query 1:

WITH days ( id, start_date, day_start, day_end, end_date ) AS (
  SELECT ROWNUM,
         start_date,
         start_date,
         LEAST( TRUNC( start_date ) + INTERVAL '1' DAY, end_date ),
         end_date
  FROM   times
UNION ALL
  SELECT id,
         start_date,
         day_end,
         LEAST( day_end + INTERVAL '1' DAY, end_date ),
         end_date
  FROM   days
  WHERE  day_end < end_date
)
SELECT start_date,
       end_date,
       SUM( shift_end - shift_start ) AS days_worked_on_shift
FROM   (
  SELECT ID,
         start_date,
         end_date,
         GREATEST( day_start, TRUNC( day_start ) + start_time ) AS shift_start,
         LEAST( day_end, TRUNC( day_start ) + end_time ) AS shift_end
  FROM   days d
         INNER JOIN
         weekly_shifts w
         ON ( TO_CHAR( d.day_start, 'DY' ) = w.shift_day )
)
GROUP BY id, start_date, end_date;

Result:

START_DATE          END_DATE            DAYS_WORKED_ON_SHIFT
------------------- ------------------- --------------------
2017-02-21 07:52:32 2017-02-22 09:56:32 0.414259259259259259
2017-02-21 09:52:32 2017-02-23 17:52:32 1.078148148148148148

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solved Calculate time diffrence in SQL with shifts