我正在使用Postgres（PL / pgSQL）开发一个算法，我需要计算两个时间戳之间的工作小时数，考虑到周末不工作，剩下的时间只计算在上午8点到下午15点
示例：
从12月3日下午14点到12月4日上午9点应该算2个小时：
3rd = 1, 4th = 1
从12月3日下午15点到12月7日上午8点应该算上8个小时：
3rd = 0, 4th = 8, 5th = 0, 6th = 0, 7th = 0
考虑小时分数也很棒。
答案 0 :(得分：27)
根据您的问题， 工作时间 是： Mo-Fr，08：00-15：00 。
以 1小时为单位进行操作。分数被忽略，因此不是精确而是简单：
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';如果结束大于开始，则函数generate_series()生成一行，而对于每个完整给定间隔（1小时），函数EXTRACT()生成另一行。此输入 每小时计算 。要忽略小数小时，请从结尾减去1小时。并且不要计算在14:00之前开始的小时数。
对SQL Fiddle.使用字段模式 ISODOW 而不是DOW来简化表达式。星期日返回7而不是0。
对time进行简单（且非常便宜）演员可以轻松识别符合条件的小时数。
忽略一小时的分数，即使间隔开始和结束的分数加起来一小时或更长时间。
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
查询：
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;
为了获得更高的精度，您可以使用更小的时间单位。例如，5分钟的切片：
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;
单位越小，成本越高。
LATERAL的清洁工
结合Postgres 9.3中的新Find most common elements in array with a group by功能，上述查询可以写成：
1小时精度：
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;
精确度为5分钟：
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;
这具有附加优势，不会像上述版本那样从结果中排除包含零工时的间隔。
有关LATERAL的更多信息：
或者您分别处理时间帧的开始和结束，以将精确结果提供给微秒。使查询更复杂，但更便宜和准确：
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;
* 新的范围类型为确切结果与SQL Fiddle.结合提供了更优雅的解决方案：
仅适用于一天的时间范围的简单功能：
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;
如果你的范围从不跨越多天，那就是你需要的一切 否则，使用此包装函数来处理任何间隔：
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;
呼叫：
SELECT t_id, f_worktime(t_start, t_end) AS worktime
FROM t
ORDER BY 1;
{{3}}
答案 1 :(得分：6)
这个怎么样：创建一个24 * 7行的小表，一周内每小时一行。
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);
同样为其他每天添加24行。你提供的年份或月份无关紧要，正如你稍后会看到的那样。你只需要代表一周中的所有七天。
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;
答案 2 :(得分：0)
以下功能将输入
工作开始时间
工作结束时间
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;
这将仅显示开始日期时间和结束日期时间之间的工时（以秒为单位）