SQL Server 如何将3个查询合并为1个？

Question

我想将以下三个查询压缩为一个查询，并将总计分为 3 列。哦，我该怎么做，这样我就不必宣布日期了。我希望它“知道”当前的日期、月份和年份。

DECLARE @myDate as datetime
SET @myDate = '2015-01-1'
select SUM(Amount) as 'Day Total' 
from [Accounting].[dbo].[HandPay] 
where AccountingDate>=@myDate and AccountingDate<dateadd(day,1,@myDate)

select SUM(Amount) as 'Month Total' 
from [Accounting].[dbo].[HandPay] 
where AccountingDate>=@myDate and AccountingDate<dateadd(MONTH,1,@myDate)

select SUM(Amount) as 'Day Total' 
from [Accounting].[dbo].[HandPay] 
where AccountingDate>=@myDate and AccountingDate<dateadd(year,1,@myDate)

执行此操作的最佳方法是什么？谢谢!

感谢所有超快的回复!现在这个问题已经解决了。

Answer 1

如果我正确理解了这个问题，那么这样的事情应该有效:

declare @today date = convert(date, getdate());
select
    [Day Total]   = sum(case when [AccountingDate] >= @today and [AccountingDate] < dateadd(day,   1, @today) then [Amount] else 0 end),
    [Month Total] = sum(case when [AccountingDate] >= @today and [AccountingDate] < dateadd(month, 1, @today) then [Amount] else 0 end),
    [Year Total]  = sum(case when [AccountingDate] >= @today and [AccountingDate] < dateadd(year,  1, @today) then [Amount] else 0 end)
from
    [Accounting].[dbo].[HandPay];

请注意，[月份总计] 和 [年度总计] 并不给出当前月份/年份内发生的条目的总和，而是给出总和从今天起一个月/一年内发生的条目。我不确定这是否是您想要的，但它似乎与原始查询一致。

更新:正如下面 D Stanley 所建议的，您可以稍微简化一下，因为您知道组成 [Day Total] 和 的日期范围[月总计] 总和完全包含在构成[年总计] 总和的日期范围内。这可能是这样的:

declare @today date = convert(date, getdate());
select
    [Day Total]   = sum(case when [AccountingDate] < dateadd(day,   1, @today) then [Amount] else 0 end),
    [Month Total] = sum(case when [AccountingDate] < dateadd(month, 1, @today) then [Amount] else 0 end),
    [Year Total]  = sum([Amount])
from
    [Accounting].[dbo].[HandPay]
where
    [AccountingDate] >= @today and [AccountingDate] < dateadd(year, 1, @today);