我想计算两个给定日期之间的工作日数。例如，如果我想计算 2013-01-10 和 2013-01-15 之间的工作日，结果必须是 3 个工作日（我不考虑该间隔的最后一天，我减去星期六和星期日）。我有以下代码适用于大多数情况，除了我的示例中的那个。
SELECT (DATEDIFF(day, '2013-01-10', '2013-01-15'))
- (CASE WHEN DATENAME(weekday, '2013-01-10') = 'Sunday' THEN 1 ELSE 0 END)
- (CASE WHEN DATENAME(weekday, DATEADD(day, -1, '2013-01-15')) = 'Saturday' THEN 1 ELSE 0 END)
我怎样才能做到这一点？我必须经历所有的日子并检查它们吗？或者有没有简单的方法来做到这一点。
请，请，请使用日历表。SQL Server 对国定假日、公司活动、自然灾害等一无所知。日历表相当容易构建，占用的空间非常小，如果引用足够多，它就会在内存中。
以下示例创建了一个包含 30 年日期（2000 -> 2029）的日历表，但磁盘上只需要 200 KB（如果使用页面压缩，则需要 136 KB）。这几乎可以保证小于在运行时处理某些 CTE 或其他集合所需的内存授予。
CREATE TABLE dbo.Calendar
(
dt DATE PRIMARY KEY, -- use SMALLDATETIME if < SQL Server 2008
IsWorkDay BIT
);
DECLARE @s DATE, @e DATE;
SELECT @s = '2000-01-01' , @e = '2029-12-31';
INSERT dbo.Calendar(dt, IsWorkDay)
SELECT DATEADD(DAY, n-1, '2000-01-01'), 1
FROM
(
SELECT TOP (DATEDIFF(DAY, @s, @e)+1) ROW_NUMBER()
OVER (ORDER BY s1.[object_id])
FROM sys.all_objects AS s1
CROSS JOIN sys.all_objects AS s2
) AS x(n);
SET DATEFIRST 1;
-- weekends
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE DATEPART(WEEKDAY, dt) IN (6,7);
-- Christmas
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE MONTH(dt) = 12
AND DAY(dt) = 25
AND IsWorkDay = 1;
-- continue with other holidays, known company events, etc.
现在，您要编写的查询非常简单：
SELECT COUNT(*) FROM dbo.Calendar
WHERE dt >= '20130110'
AND dt < '20130115'
AND IsWorkDay = 1;
有关日历表的更多信息：
有关没有循环的生成集的更多信息：
http://www.sqlperformance.com/tag/date-ranges
还要注意一些小事情，比如依赖DATENAME. 我见过几个应用程序中断，因为一些用户有不同的语言设置，如果你依赖WEEKDAY确保你DATEFIRST正确设置你的设置......
对于这样的事情，我倾向于维护一个日历表，其中还包括银行假期等。
我为此使用的脚本如下（请注意，我没有写它@我忘记了我在哪里找到它）
SET DATEFIRST 1
SET NOCOUNT ON
GO
--Create ISO week Function (thanks BOL)
CREATE FUNCTION ISOweek ( @DATE DATETIME )
RETURNS INT
AS
BEGIN
DECLARE @ISOweek INT
SET @ISOweek = DATEPART(wk, @DATE) + 1 - DATEPART(wk, CAST(DATEPART(yy, @DATE) AS CHAR(4)) + '0104')
--Special cases: Jan 1-3 may belong to the previous year
IF ( @ISOweek = 0 )
SET @ISOweek = dbo.ISOweek(CAST(DATEPART(yy, @DATE) - 1 AS CHAR(4)) + '12' + CAST(24 + DATEPART(DAY, @DATE) AS CHAR(2))) + 1
--Special case: Dec 29-31 may belong to the next year
IF ( ( DATEPART(mm, @DATE) = 12 )
AND ( ( DATEPART(dd, @DATE) - DATEPART(dw, @DATE) ) >= 28 )
)
SET @ISOweek = 1
RETURN(@ISOweek)
END
GO
--END ISOweek
--CREATE Easter algorithm function
--Thanks to Rockmoose (http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=45689)
CREATE FUNCTION fnDLA_GetEasterdate ( @year INT )
RETURNS CHAR(8)
AS
BEGIN
-- Easter date algorithm of Delambre
DECLARE @A INT ,
@B INT ,
@C INT ,
@D INT ,
@E INT ,
@F INT ,
@G INT ,
@H INT ,
@I INT ,
@K INT ,
@L INT ,
@M INT ,
@O INT ,
@R INT
SET @A = @YEAR % 19
SET @B = @YEAR / 100
SET @C = @YEAR % 100
SET @D = @B / 4
SET @E = @B % 4
SET @F = ( @B + 8 ) / 25
SET @G = ( @B - @F + 1 ) / 3
SET @H = ( 19 * @A + @B - @D - @G + 15 ) % 30
SET @I = @C / 4
SET @K = @C % 4
SET @L = ( 32 + 2 * @E + 2 * @I - @H - @K ) % 7
SET @M = ( @A + 11 * @H + 22 * @L ) / 451
SET @O = 22 + @H + @L - 7 * @M
IF @O > 31
BEGIN
SET @R = @O - 31 + 400 + @YEAR * 10000
END
ELSE
BEGIN
SET @R = @O + 300 + @YEAR * 10000
END
RETURN @R
END
GO
--END fnDLA_GetEasterdate
--Create the table
CREATE TABLE MyDateTable
(
FullDate DATETIME NOT NULL
CONSTRAINT PK_FullDate PRIMARY KEY CLUSTERED ,
Period INT ,
ISOWeek INT ,
WorkingDay VARCHAR(1) CONSTRAINT DF_MyDateTable_WorkDay DEFAULT 'Y'
)
GO
--End table create
--Populate table with required dates
DECLARE @DateFrom DATETIME ,
@DateTo DATETIME ,
@Period INT
SET @DateFrom = CONVERT(DATETIME, '20000101')
--yyyymmdd (1st Jan 2000) amend as required
SET @DateTo = CONVERT(DATETIME, '20991231')
--yyyymmdd (31st Dec 2099) amend as required
WHILE @DateFrom <= @DateTo
BEGIN
SET @Period = CONVERT(INT, LEFT(CONVERT(VARCHAR(10), @DateFrom, 112), 6))
INSERT MyDateTable
( FullDate ,
Period ,
ISOWeek
)
SELECT @DateFrom ,
@Period ,
dbo.ISOweek(@DateFrom)
SET @DateFrom = DATEADD(dd, +1, @DateFrom)
END
GO
--End population
/* Start of WorkingDays UPDATE */
UPDATE MyDateTable
SET WorkingDay = 'B' --B = Bank Holiday
--------------------------------EASTER---------------------------------------------
WHERE FullDate = DATEADD(dd, -2, CONVERT(DATETIME, dbo.fnDLA_GetEasterdate(DATEPART(yy, FullDate)))) --Good Friday
OR FullDate = DATEADD(dd, +1, CONVERT(DATETIME, dbo.fnDLA_GetEasterdate(DATEPART(yy, FullDate))))
--Easter Monday
GO
UPDATE MyDateTable
SET WorkingDay = 'B'
--------------------------------NEW YEAR-------------------------------------------
WHERE FullDate IN ( SELECT MIN(FullDate)
FROM MyDateTable
WHERE DATEPART(mm, FullDate) = 1
AND DATEPART(dw, FullDate) NOT IN ( 6, 7 )
GROUP BY DATEPART(yy, FullDate) )
---------------------MAY BANK HOLIDAYS(Always Monday)------------------------------
OR FullDate IN ( SELECT MIN(FullDate)
FROM MyDateTable
WHERE DATEPART(mm, FullDate) = 5
AND DATEPART(dw, FullDate) = 1
GROUP BY DATEPART(yy, FullDate) )
OR FullDate IN ( SELECT MAX(FullDate)
FROM MyDateTable
WHERE DATEPART(mm, FullDate) = 5
AND DATEPART(dw, FullDate) = 1
GROUP BY DATEPART(yy, FullDate) )
--------------------AUGUST BANK HOLIDAY(Always Monday)------------------------------
OR FullDate IN ( SELECT MAX(FullDate)
FROM MyDateTable
WHERE DATEPART(mm, FullDate) = 8
AND DATEPART(dw, FullDate) = 1
GROUP BY DATEPART(yy, FullDate) )
--------------------XMAS(Move to next working day if on Sat/Sun)--------------------
OR FullDate IN ( SELECT CASE WHEN DATEPART(dw, FullDate) IN ( 6, 7 ) THEN DATEADD(dd, +2, FullDate)
ELSE FullDate
END
FROM MyDateTable
WHERE DATEPART(mm, FullDate) = 12
AND DATEPART(dd, FullDate) IN ( 25, 26 ) )
GO
---------------------------------------WEEKENDS--------------------------------------
UPDATE MyDateTable
SET WorkingDay = 'N'
WHERE DATEPART(dw, FullDate) IN ( 6, 7 )
GO
/* End of WorkingDays UPDATE */
--SELECT * FROM MyDateTable ORDER BY 1
DROP FUNCTION fnDLA_GetEasterdate
DROP FUNCTION ISOweek
--DROP TABLE MyDateTable
SET NOCOUNT OFF
创建表后，查找工作日数很容易：
SELECT COUNT(FullDate) AS WorkingDays
FROM dbo.tbl_WorkingDays
WHERE WorkingDay = 'Y'
AND FullDate >= CONVERT(DATETIME, '10/01/2013', 103)
AND FullDate < CONVERT(DATETIME, '15/01/2013', 103)
请注意，此脚本包括英国银行假期，我不确定您在哪个地区。
这是一个计算工作日的简单函数，不包括周六和周日（当不需要计算假期时）：
CREATE FUNCTION dbo.udf_GetBusinessDays (
@START_DATE DATE,
@END_DATE DATE
)
RETURNS INT
WITH EXECUTE AS CALLER
AS
BEGIN
DECLARE @NUMBER_OF_DAYS INT = 0;
DECLARE @DAY_COUNTER INT = 0;
DECLARE @BUSINESS_DAYS INT = 0;
DECLARE @CURRENT_DATE DATE;
DECLARE @DAYNAME NVARCHAR(9)
SET @NUMBER_OF_DAYS = DATEDIFF(DAY, @START_DATE, @END_DATE);
WHILE @DAY_COUNTER <= @NUMBER_OF_DAYS
BEGIN
SET @CURRENT_DATE = DATEADD(DAY, @DAY_COUNTER, @START_DATE)
SET @DAYNAME = DATENAME(WEEKDAY, @CURRENT_DATE)
SET @DAY_COUNTER += 1
IF @DAYNAME = N'Saturday' OR @DAYNAME = N'Sunday'
BEGIN
CONTINUE
END
ELSE
BEGIN
SET @BUSINESS_DAYS += 1
END
END
RETURN @BUSINESS_DAYS
END
GO
这是我通常使用的方法（不使用日历表时）：
DECLARE @T TABLE (Date1 DATE, Date2 DATE);
INSERT @T VALUES ('20130110', '20130115'), ('20120101', '20130101'), ('20120611', '20120701');
SELECT Date1, Date2, WorkingDays
FROM @T t
CROSS APPLY
( SELECT [WorkingDays] = COUNT(*)
FROM Master..spt_values s
WHERE s.Number BETWEEN 1 AND DATEDIFF(DAY, t.date1, t.Date2)
AND s.[Type] = 'P'
AND DATENAME(WEEKDAY, DATEADD(DAY, s.number, t.Date1)) NOT IN ('Saturday', 'Sunday')
) wd
如果像我一样，你有一张带假期的桌子，你也可以添加这个：
SELECT Date1, Date2, WorkingDays
FROM @T t
CROSS APPLY
( SELECT [WorkingDays] = COUNT(*)
FROM Master..spt_values s
WHERE s.Number BETWEEN 1 AND DATEDIFF(DAY, t.date1, t.Date2)
AND s.[Type] = 'P'
AND DATENAME(WEEKDAY, DATEADD(DAY, s.number, t.Date1)) NOT IN ('Saturday', 'Sunday')
AND NOT EXISTS
( SELECT 1
FROM HolidayTable ht
WHERE ht.Date = DATEADD(DAY, s.number, t.Date1)
)
) wd
仅当您的日期在 2047 天之内时，上述方法才有效，如果您可能要计算更大的日期范围，则可以使用以下方法：
SELECT Date1, Date2, WorkingDays
FROM @T t
CROSS APPLY
( SELECT [WorkingDays] = COUNT(*)
FROM ( SELECT [Number] = ROW_NUMBER() OVER(ORDER BY s.number)
FROM Master..spt_values s
CROSS JOIN Master..spt_values s2
) s
WHERE s.Number BETWEEN 1 AND DATEDIFF(DAY, t.date1, t.Date2)
AND DATENAME(WEEKDAY, DATEADD(DAY, s.number, t.Date1)) NOT IN ('Saturday', 'Sunday')
) wd
我在 SQL SERVER 2008 (MS SQL) 中编写了我的代码。这对我来说可以。我希望它会帮助你。
DECLARE @COUNTS int,
@STARTDATE date,
@ENDDATE date
SET @STARTDATE ='01/21/2013' /*Start date in mm/dd/yyy */
SET @ENDDATE ='01/26/2013' /*End date in mm/dd/yyy */
SET @COUNTS=0
WHILE (@STARTDATE<=@ENDDATE)
BEGIN
/*Check for holidays*/
IF ( DATENAME(weekday,@STARTDATE)<>'Saturday' and DATENAME(weekday,@STARTDATE)<>'Sunday')
BEGIN
SET @COUNTS=@COUNTS+1
END
SET @STARTDATE=DATEADD(day,1,@STARTDATE)
END
/* Display the no of working days */
SELECT @COUNTS
通过结合@Aaron Bertrand 的答案和@HeavenCore 的复活节计算并添加我自己的一些代码，此代码创建了一个从 2000 年到 2049 年的日历，其中包括英国（英格兰）银行假期。根据 Aaron 的回答，用法和注意事项：
DECLARE @s DATE, @e DATE;
SELECT @s = '2000-01-01' , @e = '2049-12-31';
-- Insert statements for procedure here
CREATE TABLE dbo.Calendar
(
dt DATE PRIMARY KEY, -- use SMALLDATETIME if < SQL Server 2008
IsWorkDay BIT
);
INSERT dbo.Calendar(dt, IsWorkDay)
SELECT DATEADD(DAY, n-1, '2000-01-01'), 1
FROM
(
SELECT TOP (DATEDIFF(DAY, @s, @e)+1) ROW_NUMBER()
OVER (ORDER BY s1.[object_id])
FROM sys.all_objects AS s1
CROSS JOIN sys.all_objects AS s2
) AS x(n);
SET DATEFIRST 1;
-- weekends
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE DATEPART(WEEKDAY, dt) IN (6,7);
-- Christmas
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE IsWorkDay = 1 and MONTH(dt) = 12 and
(DAY(dt) in (25,26) or
(DAY(dt) in (27, 28) and DATEPART(WEEKDAY, dt) IN (1,2)) );
-- New Year
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE IsWorkDay = 1 and MONTH(dt) = 1 AND
( DAY(dt) = 1 or (DAY(dt) IN (2,3) AND DATEPART(WEEKDAY, dt)=1 ));
-- Easter
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE dt = DATEADD(dd, -2, CONVERT(DATETIME, dbo.fnDLA_GetEasterdate(DATEPART(yy, dt)))) --Good Friday
OR dt = DATEADD(dd, +1, CONVERT(DATETIME, dbo.fnDLA_GetEasterdate(DATEPART(yy, dt)))) --Easter Monday
-- May Day (first Monday in May)
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE MONTH(dt) = 5 AND DATEPART(WEEKDAY, dt)=1 and DAY(DT)<8;
-- Spring Bank Holiday (last Monday in May apart from 2022 when moved to include Platinum Jubilee bank holiday)
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE
(YEAR(dt)=2022 and MONTH(dt) = 6 AND DAY(dt) IN (2,3)) OR
(YEAR(dt)<>2022 and MONTH(dt) = 5 AND DATEPART(WEEKDAY, dt)=1 and DAY(DT)>24);
-- Summer Bank Holiday (last Monday in August)
UPDATE dbo.Calendar SET IsWorkDay = 0
WHERE MONTH(dt) = 8 AND DATEPART(WEEKDAY, dt)=1 and DAY(DT)>24;