怎么得到指定日期的星期一和星期日？
怎么得到指定日期的星期一和星期日？
我现在这样写：
declare @weekBegin datetime, @weekEnd datetime
select @weekBegin = DATEADD(wk, DATEDIFF(wk, 0, '2013-12-8') + 0, 0)
select @weekEnd = DATEADD(day, 6, @weekBegin)
select @weekBegin, @weekEnd
-------
如果输入日期星期日的话， 比如2013-12-8 ， 那么返回的星期一是2013-12-09 星期日死2013-12-15 跳了一星期， 如果是其他日期就是正确的，
我想让2013-12-8的星期一是2013-12-2 要怎么写？？
[解决办法]
--星期一 2013-12-07 23:51:21.150
select dateadd(dd,-datepart(weekday,getdate())+2,getdate())
--星期日 2013-12-15 23:56:50.437
select dateadd(dd,-datepart(weekday,getdate())+8,getdate())
declare @x datetime, @weekBegin datetime, @weekEnd datetime
select @x='2013-12-08' --> 输入日期
select @weekBegin=dateadd(d,-1*number,@x)
from master.dbo.spt_values
where type='P' and number between 0 and 6
and datepart(dw,dateadd(d,-1*number,@x))=2
select @weekEnd=dateadd(d,number,@x)
from master.dbo.spt_values
where type='P' and number between 0 and 6
and datepart(dw,dateadd(d,number,@x))=1
select @weekBegin '星期一',@weekEnd '星期日'
/*
星期一 星期日
----------------------- -----------------------
2013-12-02 00:00:00.000 2013-12-08 00:00:00.000
(1 row(s) affected)
*/
--定义给定的一天
DECLARE @Date DATETIME = GETDATE();
SELECT @Date AS '目前时间'
,DATEADD(DD,-1,@Date) AS '前一天'
,DATEADD(DD,1,@Date) AS '后一天'
/*月计算*/
,DATEADD(MONTH,DATEDIFF(MONTH,0,@Date),0) AS '月初'--在SQL Server中0 代表1900-01-01,通过月运算，保证日恒久为1号
,DATEADD(DD,-1,DATEADD(MONTH,1+DATEDIFF(MONTH,0,@Date),0)) AS '月末(精确到天)'--找到下月初再扣减1天，建议使用DATEADD而不要直接“-1”
,DATEADD(SS,-1,DATEADD(MONTH,1+DATEDIFF(MONTH,0,@Date),0)) AS '月末(精确到datetime的小数位)'
,DATEADD(MONTH,DATEDIFF(MONTH,0,@Date)-1,0) AS '上月第一天'
,DATEADD(DAY,-1,DATEADD(DAY,1-DATEPART(DAY,@Date),@Date)) AS '上月最后一天'
,DATEADD(MONTH,DATEDIFF(MONTH,0,@Date)+1,0) AS '下月第一天'
,DATEADD(DAY,-1,DATEADD(MONTH,2,DATEADD(DAY,1-DATEPART(DAY,@Date),@Date))) AS '下月最后一天'
/*周计算*/
,DATEADD(WEEKDAY,1-DATEPART(WEEKDAY,@Date),@Date) AS '本周第一天(周日)'--注意此处与@@datefirst的值有关
,DATEADD(WEEK,DATEDIFF(WEEK,-1,@Date),-1) AS '所在星期的星期日'--注意此处与@@datefirst的值有关
,DATEADD(DAY,2-DATEPART(WEEKDAY,@Date),@Date) AS '所在星期的第二天'--注意此处与@@datefirst的值有关,其他天数类推
,DATEADD(WEEK,-1,DATEADD(DAY,1-DATEPART(WEEKDAY,@Date),@Date)) AS '上个星期第一天(周日)'--注意此处与@@datefirst的值有关
,DATEADD(WEEK,1,DATEADD(DAY,1-DATEPART(WEEKDAY,@Date),@Date)) AS '下个星期第一天(星期日)'--注意此处与@@datefirst的值有关
,DATENAME(WEEKDAY,@Date) AS '本日是周几'
,DATEPART(WEEKDAY,@Date) AS '本日是周几'--返回值 1-星期日，2-星期一，3-星期二......7-星期六
/*年度计算*/
,DATEADD(YEAR,DATEDIFF(YEAR,0,@Date),0) AS '年初'
,DATEADD(YEAR,DATEDIFF(YEAR,-1,@Date),-1) AS '年末'
,DATEADD(YEAR,DATEDIFF(YEAR,-0,@Date)-1,0) AS '去年年初'
,DATEADD(YEAR,DATEDIFF(YEAR,-0,@Date),-1) AS '去年年末'
,DATEADD(YEAR,1+DATEDIFF(YEAR,0,@Date),0) AS '明年年初'
,DATEADD(YEAR,1+DATEDIFF(YEAR,-1,@Date),-1) AS '明年年末'
/*季度计算*/
,DATEADD(QUARTER,DATEDIFF(QUARTER,0,@Date),0) AS '本季季初'
,DATEADD(QUARTER,1+DATEDIFF(QUARTER,0,@Date),-1) AS '本季季末'
,DATEADD(QUARTER,DATEDIFF(QUARTER,0,@Date)-1,0) AS '上季季初'
,DATEADD(QUARTER,DATEDIFF(QUARTER,0,@Date),-1) AS '上季季末'
,DATEADD(QUARTER,1+DATEDIFF(QUARTER,0,@Date),0) AS '下季季初'
,DATEADD(QUARTER,2+DATEDIFF(QUARTER,0,@Date),-1) AS '下季季末'
set datefirst 1
select dateadd(day,-datepart(weekday,getdate())+1,getdate())--星期一
select dateadd(day,-datepart(weekday,getdate())+7,getdate())--星期天
