我有桌子
Date1 | Date2 | Days
-------------------------------
2017-01-25 2017-02-03 8
如何将其转换为这样的输出：
Periode | Days
--------------
January 5
February 3
答案 0 :(得分：2)
以下是根据两列的值生成给定时间段内工作日计数的一种方法，使用CROSS APPLY生成非工作日的日期，然后按{{1}进行分组每个日期的月份。
DATENAME修改
根据有关此处实际需求的评论，您可以根据DECLARE @TABLE TABLE (Date1 DATE, Date2 DATE); -- Days field doesn't matter.
INSERT @TABLE(Date1, Date2) VALUES
('2017-01-25', '2017-02-03');
WITH CTE1(N) AS (SELECT 1 FROM (VALUES (1), (1), (1), (1), (1), (1), (1), (1), (1), (1)) A(B)),
CTE2(N) AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) - 1 FROM CTE1 A CROSS JOIN CTE1 B CROSS JOIN CTE1) -- Generate numbers 0-999.
SELECT Periode = DATENAME(MONTH, D.Dates),
Days = COUNT(*)
FROM @TABLE T
CROSS APPLY
(
SELECT Dates = DATEADD(DAY, C.N, T.Date1)
FROM CTE2 C
WHERE C.N <= DATEDIFF(DAY, T.Date1, T.Date2) -- Generate all dates between Date1 and Date2.
AND DATEPART(WEEKDAY, DATEADD(DAY, C.N, T.Date1)) NOT IN (1, 7) -- Where the day isn't Saturday/Sunday.
) D
GROUP BY DATENAME(MONTH, D.Dates), DATEPART(MONTH, D.Dates)
ORDER BY DATEPART(MONTH, D.Dates)
;
列计算一个月内的实际天数：
DATETIME根据样本数据，1月份产生6.375天（6天全天加25小时9小时）和2月份2.125天（2天全天加3小时3天），共计8.5天。