我被時期試圖組一串日期,即「月」通過DATEADD分組日期和DATEDIFF
首先我聲明表:
--inserts 36 dates every 10 days
create table sales (sales_date datetime, sales_amount decimal(12,2))
insert into sales (sales_date,sales_amount)
select '20140101',1000 union all
select '20140110',1000 union all
select '20140120',1000 union all
select '20140130',1000 union all
...
然後我通過查詢分組期間條目(尺寸=精度*月)
DECLARE @precision int = 1 --number of months
SELECT
dateadd(month, (datediff(month, 0, sales_date)/@precision) * @precision, 0) as FromDate,
dateadd(month, @precision + (datediff(month, 0, sales_date)/@precision) * @precision, 0) as ToDate,
count(*) as number
FROM sales
GROUP BY
dateadd(month, (datediff(month, 0, sales_date)/@precision) * @precision, 0),
dateadd(month, @precision + (datediff(month, 0, sales_date)/@precision) * @precision, 0)
結果:
Test 1 : precision of 1 month
From : 01/01/2014, To : 01/02/2014, number : 4
From : 01/02/2014, To : 01/03/2014, number : 2
From : 01/03/2014, To : 01/04/2014, number : 3
From : 01/05/2014, To : 01/06/2014, number : 4
From : 01/06/2014, To : 01/07/2014, number : 3
From : 01/07/2014, To : 01/08/2014, number : 3
From : 01/08/2014, To : 01/09/2014, number : 3
From : 01/09/2014, To : 01/10/2014, number : 3
From : 01/10/2014, To : 01/11/2014, number : 3
From : 01/11/2014, To : 01/12/2014, number : 3
From : 01/12/2014, To : 01/01/2015, number : 2
Test 2 : precision of 2 months
From : 01/01/2014, To : 01/03/2014, number : 6
From : 01/03/2014, To : 01/05/2014, number : 6
From : 01/05/2014, To : 01/07/2014, number : 7
From : 01/07/2014, To : 01/09/2014, number : 6
From : 01/09/2014, To : 01/11/2014, number : 6
From : 01/11/2014, To : 01/01/2015, number : 5
Test 3 : precision of 3 months
From : 01/01/2014, To : 01/04/2014, number : 9
From : 01/04/2014, To : 01/07/2014, number : 10
From : 01/07/2014, To : 01/10/2014, number : 9
From : 01/10/2014, To : 01/01/2015, number : 8
Test 4 : precision of 4 months
From : 01/01/2014, To : 01/05/2014, number : 12
From : 01/05/2014, To : 01/09/2014, number : 13
From : 01/09/2014, To : 01/01/2015, number : 11
一切工作正常,直到測試5:
Test 5 : precision of 5 months
From : 01/10/2013, To : 01/03/2014, number : 6
From : 01/03/2014, To : 01/08/2014, number : 16
From : 01/08/2014, To : 01/01/2015, number : 14
第一行很討厭,我需要它在2014年1月1日像以前的精度
有什麼辦法來克服這個問題開始?
我不明白你是如何得到你得到的輸出,也就是說,我期望看到''FROM:''開始選擇列列表,但我不這樣做,所以這會導致我相信有一箇中間步驟你沒有在這裏展示給我們,這可能是你的「翻譯」錯誤發生的地方。 – 2014-11-24 16:42:07
'和WHERE的sales_date不爲空......這一行不需要'AND' – Tanner 2014-11-24 16:43:34
結果只是來自我的C#單元測試,但sql server提供的完全相同;無論如何插入和查詢 – codablank1 2014-11-24 16:45:02