如何在新列中显示汇总数据？答案

【问题标题】：How to display rollup data in new column?如何在新列中显示汇总数据？
【发布时间】：2012-01-15 04:57:30
【问题描述】：

我有以下查询，它返回 2011 年 StackOverflow 上每天 android 问题的数量。我想获得 2011 年提出的所有问题的总和。为此，我使用 @ 987654324@.

select 
  year(p.CreationDate) as [Year],
  month(p.CreationDate) as [Month],
  day(p.CreationDate) as [Day],
  count(*) as [QuestionsAskedToday]
from Posts p 
  inner join PostTags pt on p.id = pt.postid
  inner join Tags t on t.id = pt.tagid
where 
  t.tagname = 'android' and
  p.CreationDate > '2011-01-01 00:00:00'
group by year(p.CreationDate), month(p.CreationDate),day(p.CreationDate)
with rollup
order by year(p.CreationDate), month(p.CreationDate) desc,day(p.CreationDate) desc

这是输出：

2011 年每天提出的所有问题的总和显示在 QuestionsAskedToday 列本身中。

有没有办法在带有别名的新列中显示汇总？

Link to the query

【问题讨论】：

标签： android tsql rollup

【解决方案1】：

你可以采取这样的方法：Example

SELECT 
   YEAR(p.CreationDate) AS 'Year'
   , CASE
        WHEN GROUPING(MONTH(p.CreationDate)) = 0
           THEN CAST(MONTH(p.CreationDate) AS VARCHAR(2))
        ELSE 'Totals:'
     END AS 'Month'
   , CASE
        WHEN GROUPING(DAY(p.CreationDate)) = 0
        THEN CAST(DAY(p.CreationDate) AS VARCHAR(2))
        ELSE 'Totals:'
     END AS [DAY]
   , CASE
        WHEN GROUPING(MONTH(p.CreationDate)) = 0
           AND GROUPING(DAY(p.CreationDate)) = 0 
              THEN COUNT(1)
     END AS 'QuestionsAskedToday'
   , CASE
        WHEN GROUPING(MONTH(p.CreationDate)) = 1
           OR GROUPING(DAY(p.CreationDate)) = 1
              THEN COUNT(1)
     END AS 'Totals'
FROM Posts AS p
INNER JOIN PostTags AS pt ON p.id = pt.postid
INNER JOIN Tags AS t ON t.id = pt.tagid
WHERE t.tagname = 'android'
   AND p.CreationDate >= '2011-01-01'
GROUP BY ROLLUP(YEAR(p.CreationDate)
   , MONTH(p.CreationDate)
   , DAY(p.CreationDate))
ORDER BY YEAR(p.CreationDate)
   , MONTH(p.CreationDate) DESC
   , DAY(p.CreationDate) DESC

如果这是您想要的，同样的技术也可以应用于Years，如果您想查询多年并聚合它们，也可以将它们汇总到新列或它们自己的列中。

【讨论】：

这就是我想要的。谢谢。

【解决方案2】：

要将其显示为列而不是行，您可以使用SUM(COUNT(*)) OVER () 而不是ROLLUP。 (Online Demo)

SELECT YEAR(p.CreationDate)  AS [Year],
       MONTH(p.CreationDate) AS [Month],
       DAY(p.CreationDate)   AS [Day],
       COUNT(*)              AS [QuestionsAskedToday],
       SUM(COUNT(*)) OVER () AS [Total]
FROM   Posts p
       INNER JOIN PostTags pt
         ON p.id = pt.postid
       INNER JOIN Tags t
         ON t.id = pt.tagid
WHERE  t.tagname = 'android'
       AND p.CreationDate > '2011-01-01 00:00:00'
GROUP  BY YEAR(p.CreationDate),
          MONTH(p.CreationDate),
          DAY(p.CreationDate)  
ORDER  BY YEAR(p.CreationDate),
          MONTH(p.CreationDate) DESC,
          DAY(p.CreationDate) DESC

【讨论】：