Sql 包括日期边界以分段选择结果

我想在同一行中返回不同时间范围内特定度量的结果。 例如“最后30天”、“最后7天”、“最后3天”。 为此，我最初使用了

UNION

函数，并为每个时间范围创建了多个子查询。这样做的缺点是，我收集了三次相同的数据，从而增加了运行时间

一位同事建议我使用

CASE

函数对时间范围进行分段。我最初的想法是按如下方式实施：

select tp.Name, 
    case when pub.Date between DATEADD(day, -31, getdate()) and DATEADD(day, -1, getdate()) 
        then SUM(Impressions) else 0 end 'Last 30 days Impressions',
    case when pub.Date between DATEADD(day, -31, getdate()) and DATEADD(day, -1, getdate()) 
        then SUM(Revenue * rler.Rate) else 0 end 'Last 30 days Revenues',
    case when pub.Date between DATEADD(day, -8, getdate()) and DATEADD(day, -1, getdate()) 
        then SUM(Impressions) else 0 end 'Last 7 days Impressions',
    case when pub.Date between DATEADD(day, -8, getdate()) and DATEADD(day, -1, getdate()) 
        then SUM(Revenue * rler.Rate) else 0 end 'Last 7 days Revenues',
    case when pub.Date between DATEADD(day, -4, getdate()) and DATEADD(day, -1, getdate()) 
        then SUM(Impressions) else 0 end 'Last 3 days Impressions',
    case when pub.Date between DATEADD(day, -4, getdate()) and DATEADD(day, -1, getdate()) 
        then SUM(Revenue * rler.Rate) else 0 end 'Last 3 days Revenues'

from ...

where ...

group by tp.Name, tp.Kind, pub.Date

order by 'Last 30 days Impressions'

---

不幸的是，这将为每个名称、种类和日期返回一行，这不是我想要的。我认为这个问题取决于

通话组中的发布日期。我该怎么做才能克服这个问题？
你不能完全执行同事的建议，因为时间重叠。您可以执行非重叠范围，如下所示：

select tp.Name, 
        (case when pub.Date between DATEADD(day, -3, getdate()) and DATEADD(day, -1, getdate()) 
              then 'Last 3 days Impressions'
              when pub.Date between DATEADD(day, -7, getdate()) and DATEADD(day, -1, getdate()) 
              then '4-7 days Impressions'
              when pub.Date between DATEADD(day, -31, getdate()) and DATEADD(day, -1, getdate()) 
              then '8-31 days Impressions'
              else 'Older'
         end) as TimeRange,
       SUM(Impressions) as NumImpressions,
       . . . 
from . . .
where . . .
group by tp.Name, 
         (case when pub.Date between DATEADD(day, -3, getdate()) and DATEADD(day, -1, getdate()) 
               then 'Last 3 days Impressions'
               when pub.Date between DATEADD(day, -7, getdate()) and DATEADD(day, -1, getdate()) 
               then '4-7 days Impressions'
               when pub.Date between DATEADD(day, -31, getdate()) and DATEADD(day, -1, getdate()) 
               then '8-31 days Impressions'
               else 'Older'
          end)

我在回答我自己的问题。可使用以下代码实现此结果：

select tp.Name, 
    sum(case when pub.Date between DATEADD(day, -31, getdate()) and DATEADD(day, -1, getdate()) 
        then Impressions else 0 end) 'Last 30 days Impressions',
    sum(case when pub.Date between DATEADD(day, -31, getdate()) and DATEADD(day, -1, getdate()) 
        then (Revenue * rler.Rate) else 0 end) 'Last 30 days Revenues',
    sum(case when pub.Date between DATEADD(day, -8, getdate()) and DATEADD(day, -1, getdate()) 
        then Impressions else 0 end) 'Last 7 days Impressions',
    sum(case when pub.Date between DATEADD(day, -8, getdate()) and DATEADD(day, -1, getdate()) 
        then (Revenue * rler.Rate) else 0 end) 'Last 7 days Revenues',
    sum(case when pub.Date between DATEADD(day, -4, getdate()) and DATEADD(day, -1, getdate()) 
        then Impressions else 0 end) 'Last 3 days Impressions',
    sum(case when pub.Date between DATEADD(day, -4, getdate()) and DATEADD(day, -1, getdate()) 
        then (Revenue * rler.Rate) else 0 end) 'Last 3 days Revenues'

from ...

where ...

group by tp.Name, tp.Kind

order by 'Last 30 days Impressions' desc