Question

我想基于星期几和日期月份的出现次数生成，两个日期之间每个月的日期列表。假设我有@StartDate = 2016/04/01和@EndDate = 2016/09/01，我会检查@StartDate是在4月的第一个星期五，然后到@EndDate将创建每个月的第一个星期五的日期：

在@StartDate = 2016/04/12和@EndDate = 2016/09/01的情况下，我注意到@StartDate是4月的第二个星期二，然后是每个星期二的每个星期二的星期二：

如果@StartDate = 2016/04/28和@EndDate = 2016/09/01，请注意@StartDate是在4月的最后一个星期四：

在最后一种情况下，我需要验证每个月的周数，因为仅存在4个星期或5个星期的月份，我希望最后一次出现。

我做了什么？我找到了一个代码，在每个星期一的每个星期一给我一个月，我采用了一点来获得@StartDate和@EndDate：

;with  
 filler as (select row_number() over (order by a) a from (select top 100 1 as a from syscolumns) a cross join (select top 100 1 as b from syscolumns) b),
 dates as (select dateadd(month, a-1, @StartDate ) date from filler where a <= 1000 and dateadd(month, a-1, @StartDate) < @EndDate),
 FirstMonday as (
 select dateadd(day, case   datepart(weekday,Date) /*this is the case where verify the week day*/
                            when 1 then 1 
                            when 2 then 0
                            when 3 then 6
                            when 4 then 5 
                            when 5 then 4 
                            when 6 then 3
                            when 7 then 2
                        end, Date) as Date 
        ,case when datepart(weekday, @StartDate) = 1 then 3 else 2 end as Weeks /*here i verify the number of weeks to sum in the next date*/
 from   dates
 )
 select dateadd(week, Weeks, Date) as ThirdMonday
 from FirstMonday

Answer 1

所以，它是：

set @NumSemana = datepart(day, datediff(day, DATEADD(mm, DATEDIFF(mm,0,@StartDate), 0), @StartDate)/7 * 7)/7 + 1;
WITH    AllDays
  AS ( SELECT  @StartDate  AS [Date], DATEPART(month, @StartDate) as validMonth
       UNION ALL
       SELECT   DATEADD(week, 1, [Date]), 
                iif(DATEPART(month,DATEADD(week, 1, [Date])) < validMonth + @PeriodicityRepeat, validMonth, validMonth + @PeriodicityRepeat)
       FROM     AllDays
       WHERE    
            DATEPART(month,[Date]) <= DATEPART(month,@EndDate)
        and DATEPART(year,[Date]) <= DATEPART(year,@EndDate)
            ),
rankedDays 
  AS(     
    SELECT [Date], validMonth, 
           row_number() over ( partition by DATEPART( month, [Date]) order by [Date]) ascOrder,
           row_number() over ( partition by DATEPART( month, [Date]) order by [Date] desc) descOrder
    FROM   AllDays 
    WHERE DATEPART(month, [Date]) = validMonth
)
select [Date]
from rankedDays
where ((ascOrder = @NumSemana and @NumSemana <=4 )  
        or (descOrder = 1 and @NumSemana = 5) 
        or [Date] = @StartDate )
   and [Date] < @EndDate 
OPTION (MAXRECURSION 0)

Answer 2

<强>查询：

DECLARE @StartDate DATE = '2016-04-28',
        @EndDate DATE = '2016-09-01'

;WITH dates AS (
SELECT DATEADD(week, -5, @StartDate) as date_
UNION ALL
SELECT DATEADD(week,1,date_)
FROM dates
WHERE DATEADD(week,1,date_) < @enddate
), final AS (
SELECT  ROW_NUMBER() OVER (PARTITION BY DATEPART(year,date_), DATEPART(month,date_) ORDER BY date_ ASC) as RN,
        date_
FROM dates
), weeks AS (
SELECT *
FROM (VALUES
(1,1),
(2,2),
(3,3),
(4,4),
(4,5),
(5,4),
(5,5)
) as t(w1,w2)
WHERE w1 = (SELECT RN FROM final WHERE date_ = @StartDate)
)


SELECT MAX(date_) as date_
FROM final f
INNER JOIN weeks w ON f.RN = w.w2
WHERE date_ between @StartDate and @EndDate AND date_ != @StartDate
GROUP BY DATEPART(YEAR,date_), DATEPART(MONTH,date_)
ORDER BY MAX(date_) ASC

<强>输出：

适用于@StartDate = 2016/04/01和@EndDate = 2016/09/01

date_
----------
2016-05-06
2016-06-03
2016-07-01
2016-08-05

(4 row(s) affected)

适用于@StartDate = 2016/04/12和@EndDate = 2016/09/01

date_
----------
2016-05-10
2016-06-14
2016-07-12
2016-08-09

(4 row(s) affected)

适用于@StartDate = 2016/04/28和@EndDate = 2016/09/01

date_
----------
2016-05-26
2016-06-30
2016-07-28
2016-08-25

(4 row(s) affected)

根据当月的日期和发生日期生成日期列表

2 个答案: