SQL Server：一个日历月的整周总数答案

【问题标题】：SQL Server: whole weeks total in a calendar monthSQL Server：一个日历月的整周总数
【发布时间】：2016-10-17 13:24:59
【问题描述】：

我想要一个月内的每周总计。它不包括任何部分星期或未来几周。每周从周一到周日开始。

我有一个像

这样的表结构

Date          Value      -- Comments
----------------------------------------------------------------------   
2016-10-01      7        Ignore this because its not a whole  week in a month
2016-10-05      8        Week 1  
2016-10-07      5        Week 1  
2016-10-11      2        Week 2  
2016-10-15      1        Week 2    
2016-10-17      9        Ignore this because the week is not finished yet

输出

 WeekNo         Total
    41             13
    42              3

【问题讨论】：

您的预期输出是什么？只需添加
整整一周是什么意思？
例如：在当前日历月。我们将忽略 26Sep-2Oct 周和 31Oct-6Nov 周，因为它们不是当月的整周。
这意味着来自任意日期范围的值将被忽略，即使您查询连续月份的数据......这是一个有趣的谜题，但在投入时间之前，我想质疑底层规范。这真的是一个有效的要求吗？

标签： sql sql-server

【解决方案1】：

更简单的方法是构建一个 Tally“日期”表。您可以从任何 Tally Table 生成它，例如：

DECLARE @StartDate DATE = '20160101'
  , @EndDate DATE = '20161231';

WITH cte AS (
SELECT  DATEADD(DAY, n - 1, @StartDate) AS date
FROM    tally
WHERE   n - 1 <= DATEDIFF(DAY, @StartDate, @EndDate)
)
SELECT 
    c.date 
    ,YEAR(c.date) AS Year
    ,MONTH(c.date) AS Month
    ,DAY(c.date) AS Month
    ,DATEPART(WEEK,c.date) AS Week
    ,CASE WHEN 7<>COUNT(c.date) OVER (PARTITION BY YEAR(c.date),MONTH(c.date),DATEPART(WEEK,c.date)) THEN  0 ELSE 1 END AS isFullWeek
FROM cte c

然后你只需要将它加入到你需要的任何查询中。

【讨论】：

【解决方案2】：

DECLARE @StartDate datetime = '2011-10-01';
DECLARE @EndDate datetime = '2016-10-31';
SELECT
  CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 2, tblData.RecordDate) AS date) AS WeekStart,
  CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date) AS WeekEnd,
  SUM(Value) AS Total
FROM tblData

WHERE (@StartDate IS NULL
OR CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 2, tblData.RecordDate) AS date) >= CAST(@StartDate AS date))
AND (@EndDate IS NULL
OR CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date) <= CAST(@EndDate AS date))
AND CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date) < CAST(GETDATE() AS date)
GROUP BY CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 2, tblData.RecordDate) AS date),
         CAST(DATEADD(dd, -DATEPART(dw, tblData.RecordDate) + 8, tblData.RecordDate) AS date)

【讨论】：

【解决方案3】：

创建一个满足您要求的日历表，如下所示：

    create table calendarTable ([date] date, weekNro int)
        go

    insert into  calendarTable 
    select dateadd(d,n,'20160101'), DATEPART(WK,dateadd(d,n,'20151231')) 
    from  numbers where n<500

如果您没有数字表，则必须先创建它。像这样

SET NOCOUNT ON    
CREATE TABLE Numbers (n bigint PRIMARY KEY)    
GO    
DECLARE @numbers table(number int);  
WITH numbers(number) as  (   
SELECT 1 AS number   
UNION all   
SELECT number+1 FROM numbers WHERE number<10000  
)  
INSERT INTO @numbers(number)  
SELECT number FROM numbers OPTION(maxrecursion 10000)
INSERT INTO Numbers(n)  SELECT number FROM @numbers

然后查询您的表加入日历表，记住完成一周的实际日期，如下所示：

【讨论】：

【解决方案4】：

类似于@Kilren，但翻译成 postgres 并使用来自https://stackoverflow.com/a/11391987/10087503 的生成系列来生成日期

DECLARE @StartDate DATE = '20160101'
  , @EndDate DATE = '20161231';

WITH cte AS (
SELECT i::date AS date FROM generate_series(@StartDate, 
  @EndDate, '1 day'::interval) i
)
SELECT 
    c.date 
    ,DATE_TRUNC('month' ,c.date) AS month_trunc
    ,DATE_PART('week',c.date) AS week
    ,CASE WHEN 7<>COUNT(c.date) 
    OVER (PARTITION BY DATE_TRUNC('month' ,c.date),DATE_PART('week',c.date)) 
    THEN  0 ELSE 1 END AS is_full_week
FROM cte c

【讨论】：

【解决方案5】：

    Select DATEPART(ww, date) , SUM(Case When Comments Like '%1' then Value when Comments Like '%2' then Value else Value end)

from schema.tablename

group by DATEPART(ww,date)

如果这不起作用，我很抱歉，这是我认为构建它的唯一方法。

【讨论】：

不清楚这将如何解决问题中描述的问题