最近报表要用到一项功能，需要把数据源根据记录发生日期所在的星期序列进行分组。因此就写了两个相关SQL Function进行调用。
一、给定一个日期值，求出此日期所在星期的星期一和星期天的日期数据
例如给定一个日期2010-09-01，求出它所在星期的星期一是2010-08-30，星期天是2010-09-05
Function创建如下:
USE [MSSQL]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE FUNCTION [dbo].[My_OneDay_GetWeekFirstAndEndDay](@tmpDate DATETIME)
RETURNS @tmpTable TABLE(FirstDay DATETIME , EndDay DATETIME)
AS
BEGIN
INSERT INTO @tmpTable
SELECT a.FirstDay,b.EndDay FROM (
SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 0) AS FirstDAy
) a
LEFT JOIN (
SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 6) AS EndDay
) b
ON a.ID = b.ID
RETURN
END
Function测试:
SELECT * from My_OneDay_GetWeekFirstAndEndDay('2010-09-01')
二、以上面单个日期搜索为基础，由用户输入两个参数，一个是开始日期，一个结束日期，根据这两个参数，求出在此时期段内的所有星期的星期一和星期天的日期表并排序。
例如开始日期是2011-09-01,结束日期是2011-10-06，我们就可以得到此星期表如下:
WeekOrder FirstDay EndDay
1 2011-08-29 00:00:00.000 2011-09-04 00:00:00.000
2 2011-09-05 00:00:00.000 2011-09-11 00:00:00.000
3 2011-09-12 00:00:00.000 2011-09-18 00:00:00.000
4 2011-09-19 00:00:00.000 2011-09-25 00:00:00.000
5 2011-09-26 00:00:00.000 2011-10-02 00:00:00.000
6 2011-10-03 00:00:00.000 2011-10-09 00:00:00.000
Function创建如下:
USE [MSSQL]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE FUNCTION [dbo].[MY_Range_GetWeekFirstAndEndDays](@tmpDateSTART DATETIME,@tmpDateEND DATETIME)
RETURNS @tmpTable TABLE(WeekOrder INT,FirstDay DATETIME , EndDay DATETIME)
AS
BEGIN
DECLARE @tmpDate DATETIME
DECLARE @index INT
SET @tmpDate=@tmpDateSTART
SET @index=1
WHILE @tmpDate <=@tmpDateEND
BEGIN
INSERT INTO @tmpTable
SELECT @index,a.FirstDay,b.EndDay FROM (
SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 0) AS FirstDAy) a
LEFT JOIN (
SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 6) AS EndDay) b
ON a.ID = b.ID
SET @tmpDate=DATEADD(DAY,7,@tmpDate)
SET @index=@index+1
END
RETURN
END
Function测试:
SELECT * from My_Range_GetWeekFirstAndEndDays('2011-09-01','2011-10-06')