如何在SQL中獲取當前日期的下一個9週數字？

Question

如果我給日期2015年12月31日，它必須顯示爲

2015W53, for 2015-12-31, which means Week 53, and next follows as 
    2016W1, Next as 
    2016W2, Next as 
    2016W3 Next as... 

我的邏輯是

DECLARE @WEEK VARCHAR(2), @YEAR VARCHAR(4) 
    SELECT @YEAR = DATEPART(YY,@DATE), @WEEK = CAST(DATEPART(WK,@DATE) AS INT) % 52 ; 
    IF(CAST(DATEPART(WK,@DATE) AS INT) % 52 = 0) 
     SET @WEEK = 52; 
    IF(CAST(DATEPART(WK,@DATE) AS INT) = 53) 
     SET @YEAR = CAST(@YEAR AS INT) + 1; 
    IF (LEN(@WEEK) < 2) 
    BEGIN 
     SET @WEEK = LEFT('0' + @week, 2) 
    END 
    RETURN @YEAR + @WEEK 

但這裏2015W53缺失和IAM越來越接下來的9周，

我只是想我的一年的最後一週..， 試了很多次，但無法得到。 任何幫助非常感謝。

Answer 1

您可以連接你想要的。無需環路要麼

SELECT 
    YEAR(DATEADD(week, X.Y, BaseDate)), 
    DATEPART(ISO_WEEK, DATEADD(week, X.Y, BaseDate)) 
FROM 
    (SELECT CAST('20151231' AS date) AS BaseDate) D 
    CROSS JOIN 
    (
    VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8) 
    ) AS X(Y); 

更新 SQL Server 2008中添加，修正了上週編號

這是因爲第2點在2016年1月3日開始，根據到SQL Server幾乎工作的ISO_WEEK datepart。這與ISO week numbering不同。

Answer 2

您不能將@WEEK設置爲DATEPART(WK,@DATE) % 52，因爲有些年份已超過52周！如果每年有52周的時間，事情就會變得簡單。

爲什麼不直接確定給定的@DATE的一週，然後用DATEADD添加一個星期，看看會發生什麼？你做這9次，你得到你想要的。

例如：

DECLARE @yearsAndWeeks TABLE (Year INT, Week INT) 

DECLARE @i INT 
SET @i = 0 

DECLARE @Date DATETIME 
SET @Date = '20151231' 

WHILE @i < 9 
BEGIN 
    INSERT INTO @yearsAndWeeks (Year, Week) VALUES (DATEPART(yy, @Date), DATEPART(ISO_WEEK, @Date)) 
    SET @Date = DATEADD(WK, 1, @Date) 
    SET @i = @i + 1 
END 

SELECT * FROM @yearsAndWeeks 

Answer 3

@date是當你想在一週數據和@NumberOfWeeks是您想要的數據隨後星期的數量開始日期。請根據需要修改這些值。

--Create the temp table to hold the data 
    IF OBJECT_ID('TempDB..#Dates') IS NOT NULL 
    DROP TABLE #Dates; 

CREATE TABLE #Dates 
( [Year]   INT NOT NULL, 
    [WeekNumber] INT NOT NULL, 
    [RequiredWeek] NVARCHAR(255) NOT NULL, 
    [Date]   DATETIME NOT NULL 
); 


--DECLARE @Date  Datetime='2016-1-1'; --for testing 
--DECLARE @Date  Datetime='2016-12-31'; --for testing 
DECLARE @Date   Datetime='2015-12-31'; 
DECLARE @Days   INT; 
DECLARE @NumberOfWeeks INT; 
DECLARE @Ctr   INT=0; 

SET @NumberOfWeeks=9 

WHILE @Ctr<@NumberOfWeeks 
BEGIN 
    SET @Days=@Ctr*7 

    INSERT INTO #Dates 
    SELECT DATEPART(YEAR,@Date+@Days) AS [Year], 
      DATEPART(wk,@Date+@Days) AS [WeekNumber], 
      CAST(DATEPART(YEAR,@Date+@Days) AS VARCHAR(10))+'W'+ CAST(DATEPART(wk,@Date+@Days) AS VARCHAR(10)) AS [RequiredWeek], 
      @Date+@Days AS [Date] 
    SET @Ctr=@Ctr+1 
END 

SELECT * FROM #Dates; 

OUTPUT：

Year WeekNumber RequiredWeek Date 
2015 53   2015W53   2015-12-31 00:00:00.000 
2016 2   2016W2   2016-01-07 00:00:00.000 
2016 3   2016W3   2016-01-14 00:00:00.000 
2016 4   2016W4   2016-01-21 00:00:00.000 
2016 5   2016W5   2016-01-28 00:00:00.000 
2016 6   2016W6   2016-02-04 00:00:00.000 
2016 7   2016W7   2016-02-11 00:00:00.000 
2016 8   2016W8   2016-02-18 00:00:00.000 
2016 9   2016W9   2016-02-25 00:00:00.000 

Answer 4

爲了進一步定製，以您的需求和使該解決方案的非通用的風險，這裏是2015W53後給2016W1假設起始日期代碼「31 DEC 2015'

--Create the temp table 
IF OBJECT_ID('TempDB..#Dates') IS NOT NULL 
DROP TABLE #Dates; 

CREATE TABLE #Dates 
( [Year]   INT NOT NULL, 
    [WeekNumber] INT NOT NULL, 
    [RequiredWeek] NVARCHAR(255) NOT NULL, 
    [Date]   DATETIME NOT NULL 
); 


--DECLARE @Date Datetime='2016-1-1'; 
--DECLARE @Date Datetime='2016-12-31'; 
DECLARE @Date Datetime='2015-12-31'; 
DECLARE @Days INT; 
DECLARE @NumberOfWeeks INT; 
DECLARE @Ctr INT=0; 

SET @NumberOfWeeks=9 

WHILE @Ctr<@NumberOfWeeks 
BEGIN 
    IF (@Date ='2015-12-31' AND @Ctr=1) -- To handle 1st week of Jan 2016 
    SET @Days=@Ctr+1 
    else if (@Date ='2015-12-31' AND @Ctr=0) --To Handle last week of Dec 2015 
    SET @Days=(@Ctr)*7 
    else 
    SET @Days=(@Ctr-1)*7 --for rest of the weeks of 2016 

    INSERT INTO #Dates 
    SELECT DATEPART(YEAR,@Date+@Days) AS [Year], 
      DATEPART(wk,@Date+@Days) AS [WeekNumber], 
      CAST(DATEPART(YEAR,@Date+@Days) AS VARCHAR(10))+'W'+ CAST(DATEPART(wk,@Date+@Days) AS VARCHAR(10)) AS [RequiredWeek], 
      @Date+@Days AS [Date] 
    SET @Ctr=@Ctr+1 
END 

SELECT * FROM #Dates;