我有一个表,我们称它为 My_Table
,它有一个 Created
日期时间列(在 SQL Server 中),我试图提取一个报告,显示历史如何在特定时间按月将许多行添加到 My_Table
。现在我知道我可以通过以下方式显示每个月添加的数量:
SELECT YEAR(MT.Created), MONTH(MT.Created), COUNT(*) AS [Total Added]
FROM My_Table MT
GROUP BY YEAR(MT.Created), MONTH(MT.Created)
ORDER BY YEAR(MT.Created), MONTH(MT.Created)
这会返回类似的东西:
YEAR MONTH Total Added
-----------------------------
2009 01 25
2009 02 127
2009 03 241
但是,我想获得给定时间段内的总列表大小(随便怎么称呼;运行总计、累计总和、历史报告):
YEAR MONTH Total Size
-----------------------------
-- 2008 12 325
2009 01 350
2009 02 477
2009 03 718
我正在尝试这个:
SELECT YEAR(MT.Created)
, MONTH(MT.Created)
,(
SELECT COUNT(*) FROM My_Table MT_int
WHERE MT_int.Created BETWEEN
CAST('2009/01/01' AS datetime)
AND DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,MT.Created)+1,0))
-- the last day of the current month
-- (Additional conditions can go here)
) AS [Total added this month]
FROM My_Table MT
WHERE MT.Created > CAST('2009/01/01' AS datetime)
GROUP BY YEAR(MT.Created), MONTH(MT.Created)
ORDER BY YEAR(MT.Created), MONTH(MT.Created)
但是,SQL Server 响应此错误:
Msg 8120, Level 16, State 1, Line 1
Column 'My_Table .Created' is invalid in the select list because
it is not contained in either an aggregate function or the GROUP BY clause.
我只是知道我错过了一些明显的东西,但在走开并回来盯着它看了一会儿之后,我不知所措。因此,如果有人愿意指出我在地球上遗漏了什么(或指出更好的方法),我将永远感激不已。
最佳答案
“运行”表示逐行。因此,一种方法是对前几个月求和并将其添加到当前月份。为了处理年份界限,您还需要每组的最小/最大日期。 CROSS APPLY 有点 RBAR,但清楚(呃?)发生了什么。
;WITH cTE AS
(
SELECT
MIN(Created) AS FirstPerGroup,
MAX(Created) AS LastPerGroup,
YEAR(MT.Created) AS yr, MONTH(MT.Created) AS mth, COUNT(*) AS [Monthly Total Added]
FROM MY_Table MT
GROUP BY YEAR(MT.Created), MONTH(MT.Created)
)
SELECT
C1.yr, c1.mth, SUM(C1.[Monthly Total Added]),
ISNULL(PreviousTotal, 0) + SUM(C1.[Monthly Total Added]) AS RunningTotal
FROM
cTE c1
CROSS APPLY
(SELECT SUM([Monthly Total Added]) AS PreviousTotal FROM cTE c2 WHERE c2.LastPerGroup < C1.FirstPerGroup) foo
GROUP BY
C1.yr, c1.mth, PreviousTotal
ORDER BY
C1.yr, c1.mth
关于sql - 计算运行总计时出错(前几个时期的累计),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4107479/