我正在使用 Postgres (PL/pgSQL) 开发一种算法，我需要计算 2 个时间戳之间的工作小时数，同时考虑到周末不工作，其余时间仅从上午 8 点到下午 15 点计算。
例子：
从 12 月 3 日下午 14 点到 12 月 4 日上午 9 点应该算 2 小时：
3rd = 1, 4th = 1
从 12 月 3 日下午 15 点到 12 月 7 日上午 8 点应该算 8 小时：
3rd = 0, 4th = 8, 5th = 0, 6th = 0, 7th = 0
考虑小时分数也很好。
According to your question working hours are: Mo–Fr, 08:00–15:00.
Operating on units of 1 hour. Fractions are ignored, therefore not precise but simple:
SELECT count(*) AS work_hours
FROM generate_series (timestamp '2013-06-24 13:30'
, timestamp '2013-06-24 15:29' - interval '1h'
, interval '1h') h
WHERE EXTRACT(ISODOW FROM h) < 6
AND h::time >= '08:00'
AND h::time <= '14:00';The function generate_series() generates one row if the end is greater than the start and another row for every full given interval (1 hour). This wold count every hour entered into. To ignore fractional hours, subtract 1 hour from the end. And don't count hours starting before 14:00.
Use the field pattern ISODOW instead of DOW for EXTRACT() to simplify expressions. Returns 7 instead of 0 for Sundays.
A simple (and very cheap) cast to time makes it easy to identify qualifying hours.
Fractions of an hour are ignored, even if fractions at begin and end of the interval would add up to an hour or more.
CREATE TEMP TABLE t (t_id int PRIMARY KEY, t_start timestamp, t_end timestamp);
INSERT INTO t VALUES
(1, '2009-12-03 14:00', '2009-12-04 09:00')
,(2, '2009-12-03 15:00', '2009-12-07 08:00') -- examples in question
,(3, '2013-06-24 07:00', '2013-06-24 12:00')
,(4, '2013-06-24 12:00', '2013-06-24 23:00')
,(5, '2013-06-23 13:00', '2013-06-25 11:00')
,(6, '2013-06-23 14:01', '2013-06-24 08:59'); -- max. fractions at begin and end
Query:
SELECT t_id, count(*) AS work_hours
FROM (
SELECT t_id, generate_series (t_start, t_end - interval '1h', interval '1h') AS h
FROM t
) sub
WHERE EXTRACT(ISODOW FROM h) < 6
AND h::time >= '08:00'
AND h::time <= '14:00'
GROUP BY 1
ORDER BY 1;
To get more precision you can use smaller time units. 5-minute slices for instance:
SELECT t_id, count(*) * interval '5 min' AS work_interval
FROM (
SELECT t_id, generate_series (t_start, t_end - interval '5 min', interval '5 min') AS h
FROM t
) sub
WHERE EXTRACT(ISODOW FROM h) < 6
AND h::time >= '08:00'
AND h::time <= '14:55' -- 15.00 - interval '5 min'
GROUP BY 1
ORDER BY 1;
The smaller the unit the higher the cost.
LATERAL in Postgres 9.3+In combination with the new LATERAL feature in Postgres 9.3, the above query can then be written as:
1-hour precision:
SELECT t.t_id, h.work_hours
FROM t
LEFT JOIN LATERAL (
SELECT count(*) AS work_hours
FROM generate_series (t.t_start, t.t_end - interval '1h', interval '1h') h
WHERE EXTRACT(ISODOW FROM h) < 6
AND h::time >= '08:00'
AND h::time <= '14:00'
) h ON TRUE
ORDER BY 1;
5-minute precision:
SELECT t.t_id, h.work_interval
FROM t
LEFT JOIN LATERAL (
SELECT count(*) * interval '5 min' AS work_interval
FROM generate_series (t.t_start, t.t_end - interval '5 min', interval '5 min') h
WHERE EXTRACT(ISODOW FROM h) < 6
AND h::time >= '08:00'
AND h::time <= '14:55'
) h ON TRUE
ORDER BY 1;
This has the additional advantage that intervals containing zero working hours are not excluded from the result like in the above versions.
More about LATERAL:
Or you deal with start and end of the time frame separately to get exact results to the microsecond. Makes the query more complex, but cheaper and exact:
WITH var AS (SELECT '08:00'::time AS v_start
, '15:00'::time AS v_end)
SELECT t_id
, COALESCE(h.h, '0') -- add / subtract fractions
- CASE WHEN EXTRACT(ISODOW FROM t_start) < 6
AND t_start::time > v_start
AND t_start::time < v_end
THEN t_start - date_trunc('hour', t_start)
ELSE '0'::interval END
+ CASE WHEN EXTRACT(ISODOW FROM t_end) < 6
AND t_end::time > v_start
AND t_end::time < v_end
THEN t_end - date_trunc('hour', t_end)
ELSE '0'::interval END AS work_interval
FROM t CROSS JOIN var
LEFT JOIN ( -- count full hours, similar to above solutions
SELECT t_id, count(*)::int * interval '1h' AS h
FROM (
SELECT t_id, v_start, v_end
, generate_series (date_trunc('hour', t_start)
, date_trunc('hour', t_end) - interval '1h'
, interval '1h') AS h
FROM t, var
) sub
WHERE EXTRACT(ISODOW FROM h) < 6
AND h::time >= v_start
AND h::time <= v_end - interval '1h'
GROUP BY 1
) h USING (t_id)
ORDER BY 1;
tsrangeThe new range types offer a more elegant solution for exact results in combination with the intersection operator *:
Simple function for time ranges spanning only one day:
CREATE OR REPLACE FUNCTION f_worktime_1day(_start timestamp, _end timestamp)
RETURNS interval AS
$func$ -- _start & _end within one calendar day! - you may want to check ...
SELECT CASE WHEN extract(ISODOW from _start) < 6 THEN (
SELECT COALESCE(upper(h) - lower(h), '0')
FROM (
SELECT tsrange '[2000-1-1 08:00, 2000-1-1 15:00)' -- hours hard coded
* tsrange( '2000-1-1'::date + _start::time
, '2000-1-1'::date + _end::time ) AS h
) sub
) ELSE '0' END
$func$ LANGUAGE sql IMMUTABLE;
If your ranges never span multiple days, that's all you need.
Else, use this wrapper function to deal with any interval:
CREATE OR REPLACE FUNCTION f_worktime(_start timestamp
, _end timestamp
, OUT work_time interval) AS
$func$
BEGIN
CASE _end::date - _start::date -- spanning how many days?
WHEN 0 THEN -- all in one calendar day
work_time := f_worktime_1day(_start, _end);
WHEN 1 THEN -- wrap around midnight once
work_time := f_worktime_1day(_start, NULL)
+ f_worktime_1day(_end::date, _end);
ELSE -- multiple days
work_time := f_worktime_1day(_start, NULL)
+ f_worktime_1day(_end::date, _end)
+ (SELECT count(*) * interval '7:00' -- workday hard coded!
FROM generate_series(_start::date + 1
, _end::date - 1, '1 day') AS t
WHERE extract(ISODOW from t) < 6);
END CASE;
END
$func$ LANGUAGE plpgsql IMMUTABLE;
Call:
SELECT t_id, f_worktime(t_start, t_end) AS worktime
FROM t
ORDER BY 1;
怎么样：创建一个 24*7 行的小表，每周每小时一行。
CREATE TABLE hours (
hour timestamp not null,
is_working boolean not null
);
INSERT INTO hours (hour, is_working) VALUES
('2009-11-2 00:00:00', false),
('2009-11-2 01:00:00', false),
. . .
('2009-11-2 08:00:00', true),
. . .
('2009-11-2 15:00:00', true),
('2009-11-2 16:00:00', false),
. . .
('2009-11-2 23:00:00', false);
同样，为其他每一天添加 24 行。正如您稍后会看到的那样，您给出的年份或月份并不重要。您只需要代表一周中的所有 7 天。
SELECT t.id, t.start, t.end, SUM(CASE WHEN h.is_working THEN 1 ELSE 0 END) AS hours_worked
FROM mytable t JOIN hours h
ON (EXTRACT(DOW FROM TIMESTAMP h.hour) BETWEEN EXTRACT(DOW FROM TIMESTAMP t.start)
AND EXTRACT(DOW FROM TIMESTAMP t.end))
AND (EXTRACT(DOW FROM TIMESTAMP h.hour) > EXTRACT(DOW FROM TIMESTAMP t.start)
OR EXTRACT(HOUR FROM TIMESTAMP h.hour) >= EXTRACT(HOUR FROM TIMESTAMP t.start))
AND (EXTRACT(DOW FROM TIMESTAMP h.hour) < EXTRACT(DOW FROM TIMESTAMP t.end)
OR EXTRACT(HOUR FROM TIMESTAMP h.hour) <= EXTRACT(HOUR FROM TIMESTAMP t.end))
GROUP BY t.id, t.start, t.end;
以下函数将输入一天的
工作开始时间 一天的
工作结束时间 一天的
开始时间
结束时间
-- helper function
CREATE OR REPLACE FUNCTION get_working_time_in_a_day(sdt TIMESTAMP, edt TIMESTAMP, swt TIME, ewt TIME) RETURNS INT AS
$$
DECLARE
sd TIMESTAMP; ed TIMESTAMP; swdt TIMESTAMP; ewdt TIMESTAMP; seconds INT;
BEGIN
swdt = sdt::DATE || ' ' || swt; -- work start datetime for a day
ewdt = sdt::DATE || ' ' || ewt; -- work end datetime for a day
IF (sdt < swdt AND edt <= swdt) -- case 1 and 2
THEN
seconds = 0;
END IF;
IF (sdt < swdt AND edt > swdt AND edt <= ewdt) -- case 3 and 4
THEN
seconds = EXTRACT(EPOCH FROM (edt - swdt));
END IF;
IF (sdt < swdt AND edt > swdt AND edt > ewdt) -- case 5
THEN
seconds = EXTRACT(EPOCH FROM (ewdt - swdt));
END IF;
IF (sdt = swdt AND edt > swdt AND edt <= ewdt) -- case 6 and 7
THEN
seconds = EXTRACT(EPOCH FROM (edt - sdt));
END IF;
IF (sdt = swdt AND edt > ewdt) -- case 8
THEN
seconds = EXTRACT(EPOCH FROM (ewdt - sdt));
END IF;
IF (sdt > swdt AND edt <= ewdt) -- case 9 and 10
THEN
seconds = EXTRACT(EPOCH FROM (edt - sdt));
END IF;
IF (sdt > swdt AND sdt < ewdt AND edt > ewdt) -- case 11
THEN
seconds = EXTRACT(EPOCH FROM (ewdt - sdt));
END IF;
IF (sdt >= ewdt AND edt > ewdt) -- case 12 and 13
THEN
seconds = 0;
END IF;
RETURN seconds;
END;
$$
LANGUAGE plpgsql;
-- Get work time difference
CREATE OR REPLACE FUNCTION get_working_time(sdt TIMESTAMP, edt TIMESTAMP, swt TIME, ewt TIME) RETURNS INT AS
$$
DECLARE
seconds INT = 0;
strst VARCHAR(9) = ' 00:00:00';
stret VARCHAR(9) = ' 23:59:59';
tend TIMESTAMP; tempEdt TIMESTAMP;
x int;
BEGIN
<<test>>
WHILE sdt <= edt LOOP
tend = sdt::DATE || stret; -- get the false end datetime for start time
IF edt >= tend
THEN
tempEdt = tend;
ELSE
tempEdt = edt;
END IF;
-- skip saturday and sunday
x = EXTRACT(DOW FROM sdt);
if (x > 0 AND x < 6)
THEN
seconds = seconds + get_working_time_in_a_day(sdt, tempEdt, swt, ewt);
ELSE
-- RAISE NOTICE 'MISSED A DAY';
END IF;
sdt = (sdt + (INTERVAL '1 DAY'))::DATE || strst;
END LOOP test;
--RAISE NOTICE 'diff in minutes = %', (seconds / 60);
RETURN seconds;
END;
$$
LANGUAGE plpgsql;
-- Table Definition
DROP TABLE IF EXISTS test_working_time;
CREATE TABLE test_working_time(
pk SERIAL PRIMARY KEY,
start_datetime TIMESTAMP,
end_datetime TIMESTAMP,
start_work_time TIME,
end_work_time TIME
);
-- Test data insertion
INSERT INTO test_working_time VALUES
(1, '2015-11-03 01:00:00', '2015-11-03 07:00:00', '08:00:00', '22:00:00'),
(2, '2015-11-03 01:00:00', '2015-11-04 07:00:00', '08:00:00', '22:00:00'),
(3, '2015-11-03 01:00:00', '2015-11-05 07:00:00', '08:00:00', '22:00:00'),
(4, '2015-11-03 01:00:00', '2015-11-06 07:00:00', '08:00:00', '22:00:00'),
(5, '2015-11-03 01:00:00', '2015-11-07 07:00:00', '08:00:00', '22:00:00'),
(6, '2015-11-03 01:00:00', '2015-11-03 08:00:00', '08:00:00', '22:00:00'),
(7, '2015-11-03 01:00:00', '2015-11-04 08:00:00', '08:00:00', '22:00:00'),
(8, '2015-11-03 01:00:00', '2015-11-05 08:00:00', '08:00:00', '22:00:00'),
(9, '2015-11-03 01:00:00', '2015-11-06 08:00:00', '08:00:00', '22:00:00'),
(10, '2015-11-03 01:00:00', '2015-11-07 08:00:00', '08:00:00', '22:00:00'),
(11, '2015-11-03 01:00:00', '2015-11-03 11:00:00', '08:00:00', '22:00:00'),
(12, '2015-11-03 01:00:00', '2015-11-04 11:00:00', '08:00:00', '22:00:00'),
(13, '2015-11-03 01:00:00', '2015-11-05 11:00:00', '08:00:00', '22:00:00'),
(14, '2015-11-03 01:00:00', '2015-11-06 11:00:00', '08:00:00', '22:00:00'),
(15, '2015-11-03 01:00:00', '2015-11-07 11:00:00', '08:00:00', '22:00:00'),
(16, '2015-11-03 01:00:00', '2015-11-03 22:00:00', '08:00:00', '22:00:00'),
(17, '2015-11-03 01:00:00', '2015-11-04 22:00:00', '08:00:00', '22:00:00'),
(18, '2015-11-03 01:00:00', '2015-11-05 22:00:00', '08:00:00', '22:00:00'),
(19, '2015-11-03 01:00:00', '2015-11-06 22:00:00', '08:00:00', '22:00:00'),
(20, '2015-11-03 01:00:00', '2015-11-07 22:00:00', '08:00:00', '22:00:00'),
(21, '2015-11-03 01:00:00', '2015-11-03 23:00:00', '08:00:00', '22:00:00'),
(22, '2015-11-03 01:00:00', '2015-11-04 23:00:00', '08:00:00', '22:00:00'),
(23, '2015-11-03 01:00:00', '2015-11-05 23:00:00', '08:00:00', '22:00:00'),
(24, '2015-11-03 01:00:00', '2015-11-06 23:00:00', '08:00:00', '22:00:00'),
(25, '2015-11-03 01:00:00', '2015-11-07 23:00:00', '08:00:00', '22:00:00'),
(26, '2015-11-03 08:00:00', '2015-11-03 11:00:00', '08:00:00', '22:00:00'),
(27, '2015-11-03 08:00:00', '2015-11-04 11:00:00', '08:00:00', '22:00:00'),
(28, '2015-11-03 08:00:00', '2015-11-05 11:00:00', '08:00:00', '22:00:00'),
(29, '2015-11-03 08:00:00', '2015-11-06 11:00:00', '08:00:00', '22:00:00'),
(30, '2015-11-03 08:00:00', '2015-11-07 11:00:00', '08:00:00', '22:00:00'),
(31, '2015-11-03 08:00:00', '2015-11-03 22:00:00', '08:00:00', '22:00:00'),
(32, '2015-11-03 08:00:00', '2015-11-04 22:00:00', '08:00:00', '22:00:00'),
(33, '2015-11-03 08:00:00', '2015-11-05 22:00:00', '08:00:00', '22:00:00'),
(34, '2015-11-03 08:00:00', '2015-11-06 22:00:00', '08:00:00', '22:00:00'),
(35, '2015-11-03 08:00:00', '2015-11-07 22:00:00', '08:00:00', '22:00:00'),
(36, '2015-11-03 08:00:00', '2015-11-03 23:00:00', '08:00:00', '22:00:00'),
(37, '2015-11-03 08:00:00', '2015-11-04 23:00:00', '08:00:00', '22:00:00'),
(38, '2015-11-03 08:00:00', '2015-11-05 23:00:00', '08:00:00', '22:00:00'),
(39, '2015-11-03 08:00:00', '2015-11-06 23:00:00', '08:00:00', '22:00:00'),
(40, '2015-11-03 08:00:00', '2015-11-07 23:00:00', '08:00:00', '22:00:00'),
(41, '2015-11-03 12:00:00', '2015-11-03 18:00:00', '08:00:00', '22:00:00'),
(42, '2015-11-03 12:00:00', '2015-11-04 18:00:00', '08:00:00', '22:00:00'),
(43, '2015-11-03 12:00:00', '2015-11-05 18:00:00', '08:00:00', '22:00:00'),
(44, '2015-11-03 12:00:00', '2015-11-06 18:00:00', '08:00:00', '22:00:00'),
(45, '2015-11-03 12:00:00', '2015-11-07 18:00:00', '08:00:00', '22:00:00'),
(46, '2015-11-03 12:00:00', '2015-11-03 22:00:00', '08:00:00', '22:00:00'),
(47, '2015-11-03 12:00:00', '2015-11-04 22:00:00', '08:00:00', '22:00:00'),
(48, '2015-11-03 12:00:00', '2015-11-05 22:00:00', '08:00:00', '22:00:00'),
(49, '2015-11-03 12:00:00', '2015-11-06 22:00:00', '08:00:00', '22:00:00'),
(50, '2015-11-03 12:00:00', '2015-11-07 22:00:00', '08:00:00', '22:00:00'),
(51, '2015-11-03 12:00:00', '2015-11-03 23:00:00', '08:00:00', '22:00:00'),
(52, '2015-11-03 12:00:00', '2015-11-04 23:00:00', '08:00:00', '22:00:00'),
(53, '2015-11-03 12:00:00', '2015-11-05 23:00:00', '08:00:00', '22:00:00'),
(54, '2015-11-03 12:00:00', '2015-11-06 23:00:00', '08:00:00', '22:00:00'),
(55, '2015-11-03 12:00:00', '2015-11-07 23:00:00', '08:00:00', '22:00:00'),
(56, '2015-11-03 22:00:00', '2015-11-03 23:00:00', '08:00:00', '22:00:00'),
(57, '2015-11-03 22:00:00', '2015-11-04 23:00:00', '08:00:00', '22:00:00'),
(58, '2015-11-03 22:00:00', '2015-11-05 23:00:00', '08:00:00', '22:00:00'),
(59, '2015-11-03 22:00:00', '2015-11-06 23:00:00', '08:00:00', '22:00:00'),
(60, '2015-11-03 22:00:00', '2015-11-07 23:00:00', '08:00:00', '22:00:00'),
(61, '2015-11-03 22:30:00', '2015-11-03 23:30:00', '08:00:00', '22:00:00'),
(62, '2015-11-03 22:30:00', '2015-11-04 23:30:00', '08:00:00', '22:00:00'),
(63, '2015-11-03 22:30:00', '2015-11-05 23:30:00', '08:00:00', '22:00:00'),
(64, '2015-11-03 22:30:00', '2015-11-06 23:30:00', '08:00:00', '22:00:00'),
(65, '2015-11-03 22:30:00', '2015-11-07 23:30:00', '08:00:00', '22:00:00');
-- select query to get work time difference
SELECT
start_datetime,
end_datetime,
start_work_time,
end_work_time,
get_working_time(start_datetime, end_datetime, start_work_time, end_work_time) AS diff_in_minutes
FROM
test_working_time;
这将仅给出开始日期时间和结束日期时间之间的工作时间（以秒为单位）的差异