注：周节点是根据中国习惯，视周一为起，周日为末。
/*--------------------------------- 函数：获取某日期的特定起止日期v0.02 Author:AhDung Update:201607251729。无论@@datefirst为何值，均不影响周节点 ---------------------------------*/ ALTER FUNCTION dbo.FGetSpecialDate_ahdung(@date DATE, @SpcDate VARCHAR(20)) RETURNS DATE AS BEGIN IF @date IS NULL RETURN NULL IF @SpcDate IN ('YearBeg','YB','NC','年初') RETURN DATENAME(YEAR,@date)+'-01-01' ELSE IF @SpcDate IN ('YearEnd','YE','NW','年尾','年末') RETURN DATENAME(YEAR,@date)+'-12-31' ELSE IF @SpcDate IN ('QuarterBeg','QtBeg','QB','JC','季初') RETURN DATENAME(YEAR,@date)+CASE WHEN MONTH(@date)<=3 THEN '-01' WHEN MONTH(@date)<=6 THEN '-04' WHEN MONTH(@date)<=9 THEN '-07' ELSE '-10' END +'-01' ELSE IF @SpcDate IN ('QuarterEnd','QtEnd','QE','JW','季尾','季末') RETURN DATENAME(YEAR,@date)+CASE WHEN MONTH(@date)<=3 THEN '-03-31' WHEN MONTH(@date)<=6 THEN '-06-30' WHEN MONTH(@date)<=9 THEN '-09-30' ELSE '-12-31' END ELSE IF @SpcDate IN ('MonBeg','MB','YC','月初') RETURN CONVERT(CHAR(7),@date,120)+'-01' ELSE IF @SpcDate IN ('MonEnd','ME','YW','月尾','月末') RETURN DATEADD(DAY,-1,CONVERT(CHAR(7),DATEADD(MONTH,1,@date),120)+'-01') ELSE IF @SpcDate IN ('WeekBeg','WB','ZY','周一','WeekEnd','WE','ZR','ZM','周日','周末') BEGIN DECLARE @dw INT=DATEPART(dw,@date) DECLARE @diff INT = 9-@@DATEFIRST DECLARE @d INT= CASE WHEN @dw<@diff THEN @dw+7 ELSE @dw END IF @SpcDate IN ('WeekBeg','WB','ZY','周一') RETURN DATEADD(DAY,@diff-@d,@date) RETURN DATEADD(DAY,@diff-@d+6,@date) END RETURN @date END
