SQL Server 2008中的「交叉表」查詢

Question

使用SQL Server 2008，查找一個表，但查找特定的輸出。當前的表，命名fmCalendar：

>Date  Calendar Days 
>12/30/2014 Canada  1 
>12/30/2014 Europe  1 
>12/30/2014 UK   1 
>12/30/2014 US   1 
>12/29/2014 Canada  2 
>12/29/2014 Europe  2 
>12/29/2014 UK   3 
>12/29/2014 US   3 
>... 

我想輸出看起來像這樣：

>Date  Canada Europe UK US 
>12/30/2014 1  1  1 1 
>12/29/2014 2  2  3 3 
>... 

我該怎麼辦呢？在此先感謝

Answer 1

我會質疑它像

select 
    Date, 
    Sum(case when Calendar = 'Canada' then Days else 0 end) as Canada, 
    Sum(case when Calendar = 'Europe' then Days else 0 end) as Europe, 
    Sum(case when Calendar = 'UK' then Days else 0 end) as UK, 
    Sum(case when Calendar = 'US' then Days else 0 end) as Us, 
    Sum(case when Calendar not in ('Canada','Europe','UK','US') then Days else 0 end) 
    as Other 
from 
    MyTable 
group by 
    Date 

Answer 2

你可以做一個PIVOT：

SELECT * 
FROM fmCalendar AS T 
PIVOT(SUM([days]) FOR Calendar IN ([Canada],[Europe],[UK],[US])) AS P 

Here is an sqlfiddle與演示。結果是：

╔═══════════════════╦════════╦════════╦════╦════╗ 
║  DATE  ║ CANADA ║ EUROPE ║ UK ║ US ║ 
╠═══════════════════╬════════╬════════╬════╬════╣ 
║ December, 29 2014 ║  2 ║  2 ║ 3 ║ 3 ║ 
║ December, 30 2014 ║  1 ║  1 ║ 1 ║ 1 ║ 
╚═══════════════════╩════════╩════════╩════╩════╝