Question

在SQL Server 2008中，如果我有这样的表。

Date          NoOfCases
--------------------
2013-11-27    1
2013-11-28    2
2013-11-29    1
2013-11-30    3

我希望将前一笔加到下一行的值中。这意味着输出应该是这样的：

Date          AccumulatedNoOfCases
2013-11-27    1
2013-11-28    3
2013-11-29    4
2013-11-30    7

有什么建议吗？提前谢谢。

Answer 1

你可以在同一张桌子上进行连接，日期更小或相等。

select t1.date, sum(t2.NoOfCases) as AccumulatedNoOfCases
from Table1 t1
join Table1 t2 on t2.Date <= t1.Date
group by t1.date

SqlFiddle

有了计数，我会使用简洁的cte

with cnt as (select date, count(*) as cnt from Table1
             group by date)

select t1.date, sum(t2.cnt) as AccumulateNoOfCases
FROM cnt t1
join cnt t2 on t2.date <=t1.date
group by t1.date;

请参阅SqlFiddle

使用您的数据，应该是这样的。

WITH cte as
(select [Date of hospital visit]) as dte, count(*) as cnt
 FROM DW_Epidemic_Warning
 GROUP BY [Date of hospital visit])

select t1.dte, sum(t2.cnt) as AccumulateNoOfCases
FROM cte t1
join cte t2 on t2.dte <=t1.dte
group by t1.dte;

Answer 2

您没有说明您正在使用的SQL Server版本。如果是2012年，您可以执行类似

的操作

SELECT 
  t1.date, sum(t1.NoOfCases) OVER (ORDER BY t1.date) AS AccumulatedNoOfCases
FROM Table1 t1

Answer 3

我喜欢这个：

Select c.CaseDate,
  (Select Sum(NoOfCases) 
   From Cases
   Where CaseDate <= c.CaseDate
   AND CaseDate > '2013-11-20') AS AccumulatedCases
From Cases c

显然AND CaseDate > '2013-11-20'在这种情况下完全是任意的;你可能想在那里使用一个参数。

SqlFiddle

累计SQL中的行：汇总以前的值和按日期分组的新值

3 个答案: