動態字段內容爲行的Sql

Question

我有一個SQL數據庫上執行下面的數據集

---------------------------------- 
| ID | NAME | AGE | STATUS | 
----------------------------------- 
| 1ASDF | Brenda | 21 | Single | 
----------------------------------- 
| 2FDSH | Ging | 24 | Married| 
----------------------------------- 
| 3SDFD | Judie | 18 | Widow | 
----------------------------------- 
| 4GWWX | Sophie | 21 | Married| 
----------------------------------- 
| 5JDSI | Mylene | 24 | Singe | 
----------------------------------- 

我要查詢該數據集，這樣我可以在我的結果

-------------------------------------- 
| AGE | SINGLE | MARRIED | WIDOW | 
-------------------------------------- 
| 21 | 1  | 1  | 0  | 
-------------------------------------- 
| 24 | 1  | 1  | 0  | 
-------------------------------------- 
| 18 | 0  | 0  | 1  | 
-------------------------------------- 

而且具有這種結構狀態列可以是動態的，所以會有更多列來。 這可能嗎？

Answer 1

由於您使用的是SQL Server，您可以使用PIVOT表操作是這樣的：

SELECT * 
FROM 
(
    SELECT Age, Name, Status FROM tablename 
) AS t 
PIVOT 
(
    COUNT(Name) 
    FOR Status IN(Single, Married, Widow) 
) AS p; 

SQL Fiddle Demo

---

要做到這一點動態，你必須使用動態SQL這樣的：

DECLARE @cols AS NVARCHAR(MAX); 
DECLARE @query AS NVARCHAR(MAX); 


select @cols = STUFF((SELECT distinct ',' + 
         QUOTENAME(status) 
         FROM tablename 
         FOR XML PATH(''), TYPE 
        ).value('.', 'NVARCHAR(MAX)') 
         , 1, 1, ''); 

SELECT @query = ' 
SELECT * 
FROM 
(
    SELECT Age, Name, Status FROM tablename 
) AS t 
PIVOT 
(
    COUNT(Name) 
    FOR Status IN(' +@cols + ') 
) AS p;'; 


execute(@query); 

• Updated SQL Fiddle Demo