求 第20周的星期天和星期六日期的写法？

Question

求 第20周的星期天和星期六日期的写法？

Answer 1

参考：
http://topic.csdn.net/t/20050919/10/4278688.html

Answer 2

求 第20周的星期天和星期六日期的写法？
select dateadd(wk,19,dateadd(dd,number,'2011-01-01'))
from master..spt_values 
WHERE  type='P'
and
( 
DATEPART(WEEKDAY,dateadd(dd,number,'2011-01-01'))=1
or 
DATEPART(WEEKDAY,dateadd(dd,number,'2011-01-01'))=7)and number<=6
/*-----------------------
2011-05-14 00:00:00.000
2011-05-15 00:00:00.000(2 行受影响)
*/

Answer 3

Create Function xfn_GetDate(@YEAR INT,@WEEK INT,@DAY INT)
RETURNS DATETIME
AS
BEGIN
 DECLARE @RST DATETIME
 SET @RST=CAST( (CAST(@YEAR AS VARCHAR(20))+'-01-01') AS DATETIME)
 WHILE @RST<CAST( (CAST(@YEAR AS VARCHAR(20))+'-12-31') AS DATETIME)
 BEGIN
  IF @WEEK=DATEPART(WW,@RST) AND @DAY=DATEPART(DW,@RST)
   RETURN @RST
  SET @RST=DATEADD(DD,1,@RST)
 END
 RETURN @RST
END
SELECT DBO.xfn_GetDate('2011',20,6)
SELECT DBO.xfn_GetDate('2011',20,7)

Answer 4

http://topic.csdn.net/u/20081231/10/624c68b9-e9b6-4c01-910f-c116bdd14c63.html?2546http://topic.csdn.net/u/20080523/11/08e4624a-13d1-4a6c-a9bc-7cfdd721a351.html?4574http://topic.csdn.net/u/20080801/11/2f79d062-8049-4ade-a884-01dbaa429135.html?63426

Answer 5

http://topic.csdn.net/u/20090520/22/2267467b-0c40-4a5e-8b71-24838be0ff64.html?10943