根據同一表格的不同標準在相同字段中顯示的數量

Question

說我的表格只有2個字段：Id和color。

id color 
---------- 
1 Green 
2 Red 
3 Yellow 

我希望計數顯示在一行而不是列中。

SELECT COUNT(color), color 
    FROM MYTABLE 
GROUP BY color 

這給了我：

count color 
-------------- 
10  Green 
20  Red 
15  Yellow 

我需要它顯示爲：

Green Red Yellow 
------------------- 
10  20 15 

Answer 1

select (select COUNT(color) from MyTable where color='Green') as 'Green', 
     (select COUNT(color) from MyTable where color='Red') as 'Red'. 
     (select COUNT(color) from MyTable where color='Yellow') as 'Yellow' 

Answer 2

嘗試此鏈接http://blog.programmingsolution.net/sql-server-2008/sql-server-pivot-converting-rows-to-columns-with-dynamic-query/

但如果這樣做財產以後像這

select [ID],[COLOUR] from 

(SELECT [ID],[COLOUR] FROM [dbo].[table]) as S 

Pivot (COUNT([COLOUR]) 

FOR COLOUR IN ([YELLOW],[RED],[GREEN]) 

) as P 

Answer 3

另一種方式來做到這一點（在MySQL只）是：

SELECT SUM(color = 'Green') AS "Green" 
    , SUM(color = 'Red') AS "Red" 
    , SUM(color = 'Yellow') AS "Yellow" 
FROM MyTable ; 

Answer 4

SELECT 
    COUNT(CASE Color WHEN 'Green' THEN 1 END) AS Green, 
    COUNT(CASE Color WHEN 'Red' THEN 1 END) AS Red, 
    COUNT(CASE Color WHEN 'Yellow' THEN 1 END) AS Yellow 
FROM MYTABLE 

你不需要在這裏分組。基本上，每個COUNT通過所有行，但計數只有那些Color匹配某個值。