如何在SQL中獲取當年的所有周末日期？

Question

我嘗試過，但無法獲得正確的解決方案。我想要一個列出當年所有周末日期的SQL查詢。

我想這個SQL查詢：

WITH hier(num, lvl) AS (
    SELECT 0, 1 
      UNION ALL 
    SELECT 100, 1 
      UNION ALL 
    SELECT num + 1, lvl + 1 
    FROM hier 
    WHERE lvl < 100 
) 
SELECT lvl [Week], 
convert(date,DATEADD(dw, -DATEPART(dw, DATEADD(wk,DATEDIFF(wk,0,'12/31/'+convert(nvarchar,YEAR(getdate()))), 0)+6), 
DATEADD(wk, DATEDIFF(wk,0,'12/31/'+convert(nvarchar,YEAR(getdate()))), 0)+6) - num * 7,101) [End Date] 
FROM hier a 
where num < 52 
ORDER BY [End Date] asc 

它的輸出是這樣的：

Week End date 
52 2012-01-14 
51 2012-01-21 
50 2012-01-28 
49 2012-02-04 

我想日期以從頭開始 - 因此，上述缺少一個週末，這是2012-07-01。另外，我希望星期數字顯示爲1, 2, 3...而不是52, 51...。

Answer 1

結帳this博客文章。

您的問題已詳細解釋。

DECLARE @Year AS INT, 
@FirstDateOfYear DATETIME, 
@LastDateOfYear DATETIME 
-- You can change @year to any year you desire 
SELECT @year = 2010 
SELECT @FirstDateOfYear = DATEADD(yyyy, @Year - 1900, 0) 
SELECT @LastDateOfYear = DATEADD(yyyy, @Year - 1900 + 1, 0) 
-- Creating Query to Prepare Year Data 
;WITH cte AS (
SELECT 1 AS DayID, 
@FirstDateOfYear AS FromDate, 
DATENAME(dw, @FirstDateOfYear) AS Dayname 
UNION ALL 
SELECT cte.DayID + 1 AS DayID, 
DATEADD(d, 1 ,cte.FromDate), 
DATENAME(dw, DATEADD(d, 1 ,cte.FromDate)) AS Dayname 
FROM cte 
WHERE DATEADD(d,1,cte.FromDate) < @LastDateOfYear 
) 
SELECT FromDate AS Date, Dayname 
FROM CTE 
WHERE DayName LIKE 'Sunday' 
/* 
WHERE DayName IN ('Saturday,Sunday') -- For Weekend 
WHERE DayName NOT IN ('Saturday','Sunday') -- For Weekday 
WHERE DayName LIKE 'Monday' -- For Monday 
WHERE DayName LIKE 'Sunday' -- For Sunday 
*/ 
OPTION (MaxRecursion 370) 

Answer 2

嘗試這樣做是爲了找到的第一個星期六：2012-01-01

1. 開始。如果它不是一個週六，加上每天
2. 轉到2

然後，在臨時表中添加該日期和下一個日期（星期日）。 之後，循環執行以下操作：

1. 7天和第8天添加到最後一個星期六你找到（你會得到如下週六和週日）
2. 檢查他們是否仍然在2012
3. 如果他們，將它們存儲在臨時表中並轉到1

可能有更優雅的方式，但這是我的快速&骯髒的解決方案。由於您沒有發佈任何您嘗試過的代碼，因此我會將實施留給您。

Answer 3

你可以試試這個

DECLARE @FirstDateOfYear DATETIME 
SET @FirstDateOfYear = ’2010-01-01′ 
SELECT DISTINCT DATEADD(d, number, @FirstDateOfYear), 
CASE DATEPART(dw, DATEADD(d, number, @FirstDateOfYear)) 
WHEN 7 THEN ‘Saturday’ 
WHEN 1 THEN ‘Sunday’ 
ELSE ‘Work Day’ 
END 
FROM master..spt_values 
WHERE number BETWEEN 0 AND 364 
AND (DATEPART(dw, DATEADD(d, number, @FirstDateOfYear)) = 1 OR DATEPART(dw, DATEADD(d, number, @FirstDateOfYear)) = 7) 
ORDER BY DATEADD(d, number, @FirstDateOfYear) 

Answer 4

這樣做是否有助於

DECLARE @startDate DATETIME, @endDate DATETIME 
SELECT @startDate = '2012-01-01', @endDate = '2012-12-31' 
;WITH Calender AS (
    SELECT @startDate AS dt 
    UNION ALL 
    SELECT dt + 1 FROM Calender 
    WHERE dt + 1 <= @endDate 
) 
SELECT 
dt 
,NameMonth = DATENAME(Month, dt) 
,NameDay = DATENAME (Weekday,dt) 
,WeekofYr = DATEPART(WEEK, dt) FROM Calender 
WHERE DATENAME (Weekday,dt) IN ('Sunday') 
Option(MaxRecursion 0) 

的結果（部分）

dt      NameMonth NameDay WeekofYr 
2012-01-01 00:00:00.000 January  Sunday 1 
2012-01-08 00:00:00.000 January  Sunday 2 
............................................... 
............................................... 
2012-12-30 00:00:00.000 December Sunday 53  

Answer 5

這也適用

declare @dat datetime, @add int 

set @dat = '20120101' 
set @add = datepart(w,@dat) 

set @add = 5 - @add -- friday 

set @dat = dateadd(d,@add,@dat) 

while @dat <= '20121231' 
begin 
    print @dat 
    set @dat = dateadd(d,7,@dat) 
end 

Answer 6

;with AllDaysOfYear (Day) as (
    select DATEADD(year,DATEDIFF(year,0,CURRENT_TIMESTAMP),0) --Jan 1st 
    union all 
    select DATEADD(day,1,Day) from AllDaysOfYear 
    where DATEPART(year,DATEADD(day,1,Day)) = DATEPART(year,CURRENT_TIMESTAMP) 
) 
select 
    ROW_NUMBER() OVER (ORDER BY Day) as WeekNo, 
    Day 
from 
    AllDaysOfYear 
where 
    DATEPART(weekday,Day) = DATEPART(weekday,'20120714') 
option (maxrecursion 0) 

首先，產生本年度（AllDaysInYear）一組的所有日子。然後，選擇weekday是星期六的那些人。我使用的價值（'20120714'）不是非常重要 - 它必須是從任何一年的任何星期六。我只是用它來避免需要特別的DATEFIRST或語言設置。

Answer 7

此查詢顯示如何在第一部分中獲得今年的第一天和下一年的第一天。下一年的第一天計算一次，以免不斷收到並比較年份。

;WITH cte(TheDate,NextYear) AS 
(
    SELECT CAST(CONVERT(CHAR(4),GETDATE(),112)+'0101' AS DATETIME), 
     CAST(YEAR(GETDATE())*10000+10101 AS CHAR(8)) 
    UNION ALL 
    SELECT DateAdd(d,1,TheDate),NextYear 
    FROM cte 
    WHERE DateAdd(d,1,TheDate)<NextYear 
) 
    SELECT Week = DatePart(wk,TheDate), 
     TheDate 
    FROM cte 
    WHERE DateName(dw,TheDate) in ('Saturday') 
ORDER BY TheDate 
OPTION (MAXRECURSION 366) 

Answer 8

with t as 
(
select 1 b 
union all 
select 1 b 
union all 
select 1 b 
union all 
select 1 b 
union all 
select 1 b 
union all 
select 1 b 
union all 
select 1 b 
union all 
select 1 b 
) 
select * from 
(
select 
current_timestamp 
-datepart(dy,current_timestamp) 
+row_number() over (order by t.b) d 
from t, t t1, t t2 
) tmp 
where datepart(yyyy,d)=datepart(yyyy,current_timestamp) 
     and 
     DATENAME(dw,d)='sunday'