我在数据表中有两个字段 - ＆＃34; startTime＆＃34;和＆＃34; endTime。＆＃34;这两个字段表示用户在特定任务上花费的持续时间。这些是varchar字段。所以，我们假设我们的开始时间为＆＃34; 21：05：00＆＃34;结束时间为＆＃34; 22：09：00。＆＃34;我需要代码来计算在21小时和22小时内（即9分钟）花费的总分钟数。所以，不仅仅是一个简单的微小差异，而是按小时分解。
最好的方法是什么？
到目前为止，我已经创建了一个表，它将在24小时内返回所有可能的小时数。这是一个样本：
Hour startTime endTime
0 2015-01-01 00:00:00.000 2015-01-01 01:00:00.000
1 2015-01-01 01:00:00.000 2015-01-01 02:00:00.000
2 2015-01-01 02:00:00.000 2015-01-01 03:00:00.000
我已将startTime字段从varchar转换为dateteime，并将其命名为sessionHour：
Convert(datetime, startTime) As sessionHour
此外，我还可以通过以下方式获取startTime的小时：
DateAdd(Minute, 60 * (DateDiff(Minute, 0, startTime) / 60), 0) As hourOf
除此之外，我对如何解析每小时的分钟感到迷茫。
答案 0 :(得分：2)
你非常接近。您只需要将数字表与数据相结合。我会使用CROSS APPLY。这是[{3}}最终解决方案。
示例数据
DECLARE @Durations TABLE (ID int IDENTITY(1,1), StartTime datetime, EndTime datetime);
INSERT INTO @Durations VALUES
('2015-01-01 21:05:00', '2015-01-01 22:09:00'),
('2015-01-01 01:05:00', '2015-01-01 01:20:00'),
('2015-01-01 11:05:00', '2015-01-01 13:09:00'),
('2015-01-01 15:05:00', '2015-01-01 17:50:00'),
('2015-01-01 16:30:00', '2015-01-01 17:20:00');
我从一开始就使用datetime类型，因为您已将varchar值转换为正确的datetime。
我会使用一张数字表。它应该具有与数据中最长持续时间（以小时为单位）相同的行数。它可能超过24个。通常，在数据库中为其他报告提供此类表是有用的。
DECLARE @Numbers TABLE (Number int);
INSERT INTO @Numbers VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9),(10);
-- Number of rows in this table should be more than the longest duration in hours
我需要一些参考时间点来移除datetime的分钟部分。它可以是任何日期时间，只要它没有分钟和秒。
DECLARE @VarStart datetime;
SET @VarStart = '2000-01-01';
SELECT *
FROM
@Durations AS D
CROSS APPLY
(
SELECT N.Number
FROM @Numbers AS N
WHERE N.Number <= DATEDIFF(hour, StartTime, EndTime)
) AS CA_Number
ORDER BY ID;
ID StartTime EndTime Number
1 2015-01-01 21:05:00 2015-01-01 22:09:00 0
1 2015-01-01 21:05:00 2015-01-01 22:09:00 1
2 2015-01-01 01:05:00 2015-01-01 01:20:00 0
3 2015-01-01 11:05:00 2015-01-01 13:09:00 0
3 2015-01-01 11:05:00 2015-01-01 13:09:00 1
3 2015-01-01 11:05:00 2015-01-01 13:09:00 2
4 2015-01-01 15:05:00 2015-01-01 17:50:00 0
4 2015-01-01 15:05:00 2015-01-01 17:50:00 1
4 2015-01-01 15:05:00 2015-01-01 17:50:00 2
5 2015-01-01 16:30:00 2015-01-01 17:20:00 0
5 2015-01-01 16:30:00 2015-01-01 17:20:00 1
您可以看到我们为每个原始行创建了几行，具体取决于原始行的持续时间。其余的是简单的算术。
每小时分钟
SELECT *
,DATEDIFF(minute, MaxStart, MinEnd) AS MinutesPerHour
FROM
@Durations AS D
CROSS APPLY
(
SELECT N.Number
FROM @Numbers AS N
WHERE N.Number <= DATEDIFF(hour, StartTime, EndTime)
) AS CA_Number
CROSS APPLY
(
SELECT
DATEADD(hour, CA_Number.Number, StartTime) AS HourStart
,DATEADD(hour, CA_Number.Number+1, StartTime) AS HourEnd
) AS CA_HourEnd
CROSS APPLY
(
-- Truncate to 1 hour.
SELECT
DATEADD(hour, DATEDIFF(hour, @VarStart, HourStart), @VarStart) AS HourStartFinal
,DATEADD(hour, DATEDIFF(hour, @VarStart, HourEnd), @VarStart) AS HourEndFinal
) AS CA_HourEndFinal
-- Intersect intervals [StartTime, EndTime] with [HourStartFinal, HourEndFinal]
CROSS APPLY
(
SELECT
CASE WHEN StartTime > HourStartFinal THEN StartTime ELSE HourStartFinal END AS MaxStart
,CASE WHEN EndTime < HourEndFinal THEN EndTime ELSE HourEndFinal END AS MinEnd
) AS CA_Intersect
ORDER BY ID;
在CA_HourEnd和CA_HourEndFinal中，我使用Number计算小时边界。然后相交两个间隔并计算每个交叉点的分钟数。这是结果集：
ID StartTime EndTime Number HourStart HourEnd HourStartFinal HourEndFinal MaxStart MinEnd MinutesPerHour
1 2015-01-01 21:05:00 2015-01-01 22:09:00 0 2015-01-01 21:05:00 2015-01-01 22:05:00 2015-01-01 21:00:00 2015-01-01 22:00:00 2015-01-01 21:05:00 2015-01-01 22:00:00 55
1 2015-01-01 21:05:00 2015-01-01 22:09:00 1 2015-01-01 22:05:00 2015-01-01 23:05:00 2015-01-01 22:00:00 2015-01-01 23:00:00 2015-01-01 22:00:00 2015-01-01 22:09:00 9
2 2015-01-01 01:05:00 2015-01-01 01:20:00 0 2015-01-01 01:05:00 2015-01-01 02:05:00 2015-01-01 01:00:00 2015-01-01 02:00:00 2015-01-01 01:05:00 2015-01-01 01:20:00 15
3 2015-01-01 11:05:00 2015-01-01 13:09:00 0 2015-01-01 11:05:00 2015-01-01 12:05:00 2015-01-01 11:00:00 2015-01-01 12:00:00 2015-01-01 11:05:00 2015-01-01 12:00:00 55
3 2015-01-01 11:05:00 2015-01-01 13:09:00 1 2015-01-01 12:05:00 2015-01-01 13:05:00 2015-01-01 12:00:00 2015-01-01 13:00:00 2015-01-01 12:00:00 2015-01-01 13:00:00 60
3 2015-01-01 11:05:00 2015-01-01 13:09:00 2 2015-01-01 13:05:00 2015-01-01 14:05:00 2015-01-01 13:00:00 2015-01-01 14:00:00 2015-01-01 13:00:00 2015-01-01 13:09:00 9
4 2015-01-01 15:05:00 2015-01-01 17:50:00 0 2015-01-01 15:05:00 2015-01-01 16:05:00 2015-01-01 15:00:00 2015-01-01 16:00:00 2015-01-01 15:05:00 2015-01-01 16:00:00 55
4 2015-01-01 15:05:00 2015-01-01 17:50:00 1 2015-01-01 16:05:00 2015-01-01 17:05:00 2015-01-01 16:00:00 2015-01-01 17:00:00 2015-01-01 16:00:00 2015-01-01 17:00:00 60
4 2015-01-01 15:05:00 2015-01-01 17:50:00 2 2015-01-01 17:05:00 2015-01-01 18:05:00 2015-01-01 17:00:00 2015-01-01 18:00:00 2015-01-01 17:00:00 2015-01-01 17:50:00 50
5 2015-01-01 16:30:00 2015-01-01 17:20:00 0 2015-01-01 16:30:00 2015-01-01 17:30:00 2015-01-01 16:00:00 2015-01-01 17:00:00 2015-01-01 16:30:00 2015-01-01 17:00:00 30
5 2015-01-01 16:30:00 2015-01-01 17:20:00 1 2015-01-01 17:30:00 2015-01-01 18:30:00 2015-01-01 17:00:00 2015-01-01 18:00:00 2015-01-01 17:00:00 2015-01-01 17:20:00 20
最终查询
最后，我将分钟数分组一小时：
SELECT
HourStartFinal
,SUM(DATEDIFF(minute, MaxStart, MinEnd)) AS SumMinutesPerHour
FROM
@Durations AS D
CROSS APPLY
(
SELECT N.Number
FROM @Numbers AS N
WHERE N.Number <= DATEDIFF(hour, StartTime, EndTime)
) AS CA_Number
CROSS APPLY
(
SELECT
DATEADD(hour, CA_Number.Number, StartTime) AS HourStart
,DATEADD(hour, CA_Number.Number+1, StartTime) AS HourEnd
) AS CA_HourEnd
CROSS APPLY
(
-- Truncate to 1 hour.
SELECT
DATEADD(hour, DATEDIFF(hour, @VarStart, HourStart), @VarStart) AS HourStartFinal
,DATEADD(hour, DATEDIFF(hour, @VarStart, HourEnd), @VarStart) AS HourEndFinal
) AS CA_HourEndFinal
-- Intersect intervals [StartTime, EndTime] with [HourStartFinal, HourEndFinal]
CROSS APPLY
(
SELECT
CASE WHEN StartTime > HourStartFinal THEN StartTime ELSE HourStartFinal END AS MaxStart
,CASE WHEN EndTime < HourEndFinal THEN EndTime ELSE HourEndFinal END AS MinEnd
) AS CA_Intersect
GROUP BY HourStartFinal
ORDER BY HourStartFinal;
最终结果集
HourStartFinal SumMinutesPerHour
2015-01-01 01:00:00.000 15
2015-01-01 11:00:00.000 55
2015-01-01 12:00:00.000 60
2015-01-01 13:00:00.000 9
2015-01-01 15:00:00.000 55
2015-01-01 16:00:00.000 90
2015-01-01 17:00:00.000 70
2015-01-01 21:00:00.000 55
2015-01-01 22:00:00.000 9
答案 1 :(得分：0)
您可能希望查看datepart()功能，它可以帮助您更干净地操纵日期。例如：
select @endOfHour = dateadd(hour,
1,
datetimefromparts(
datepart(year, @startTime),
datepart(month, @startTime),
datepart(day, @startTime),
datepart(hour, @startTime),
0,
0,
0));
select h.theHour, @startTime, @endOfHour, datediff(minute, @startTime, @endOfHour)
from ListOfHours as h
where datepart(hour, @startTime) = h.Hour;