从 SQL Server 中的列中透视和连接值

Question

我有这些列的表格：

ID | Name  | Value
------------------
 1 | Test1 | 0
 2 | Test2 | 1
 3 | Test3 | 0
 4 | Test4 | 0
 5 | Test5 | 1

我希望将旋转和连接的值列作为字符串

01001

Answer 1

使用FOR XML 连接。重要的是您还包括一个 ORDER BY。否则，您将无法控制值的顺序，并且可能会出现任意顺序的风险。

SELECT 
  (SELECT CAST([VALUE] AS CHAR(1)) 
   FROM yourtable
   ORDER BY ID
   FOR XML PATH ('')
  )

Answer 2

下面的代码将给出预期的结果：

SELECT @Result = @Result + CAST(VALUE AS VARCHAR)
FROM #TmpTestingTable

或者你可以使用STUFF:

SELECT STUFF(
    (   SELECT CAST(VALUE AS VARCHAR) 
        FROM #TmpTestingTable
        FOR XML PATH ('')
    ), 1, 0, '')

作为示例，我将列插入到临时表中并执行代码。

CREATE TABLE #TmpTestingTable (ID INT, Name VARCHAR (20), Value INT)

INSERT INTO #TmpTestingTable (ID, Name, Value) VALUES
(1 , 'Test1' , 0),
(2 , 'Test2' , 1),
(3 , 'Test3' , 0),
(4 , 'Test4' , 0),
(5 , 'Test5' , 1)

DECLARE @Result AS VARCHAR (100) = '';

-- using variable approach
SELECT @Result = @Result + CAST(VALUE AS VARCHAR)
FROM #TmpTestingTable

SELECT @Result

-- using STUFF approach
SELECT STUFF(
    (   SELECT CAST(VALUE AS VARCHAR) 
        FROM #TmpTestingTable
        FOR XML PATH ('')
    ), 1, 0, '')

DROP TABLE #TmpTestingTable

Answer 3

SELECT GROUP_CONCAT(Value SEPARATOR '') FROM Table

编辑：

无法在 SQL Server 上运行。看看Simulating group_concat MySQL function in Microsoft SQL Server 2005? 尝试让它工作