Question

请帮助我。这个类别是动态的，将来有多少类别必须在旋转输出中显示。

我有一张这样的桌子。

Create table [Pivot_Check]
(    
[Id] Int Identity(1,1)
,[Category] Varchar(1) 
)

Insert into [Pivot_Check] Values('A')
Insert into [Pivot_Check] Values('B')
Insert into [Pivot_Check] Values('A')
Insert into [Pivot_Check] Values('B')
Insert into [Pivot_Check] Values('C')
Insert into [Pivot_Check] Values('D')
Insert into [Pivot_Check] Values('C')
Insert into [Pivot_Check] Values('D')

Select * from [Pivot_Check]

表数据将是这样的！

Id  Category
1   A
2   B
3   A
4   B
5   C
6   D
7   C
8   D

如何获得这样的输出？

Id   A   B      C       D
```````````````````````````
1   A      NULL NULL    NULL
2   NULL   B    NULL    NULL
3   A      NULL NULL    NULL
4   NULL   B    NULL    NULL
5   NULL   NULL C       NULL
6   NULL   NULL NULL    D
7   NULL   NULL C       NULL
8   NULL   B    NULL    D

Answer 1

你可以写成：

DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)

--Get distinct values of the PIVOT Column 
SELECT @ColumnName= ISNULL(@ColumnName + ',','') 
       + QUOTENAME(Category)
FROM (SELECT DISTINCT Category FROM [Pivot_Check]) AS [Pivot_Check]

--Prepare the PIVOT query using the dynamic 
SET @DynamicPivotQuery = 
  N'SELECT Id, ' + @ColumnName + '
    FROM [Pivot_Check]
    PIVOT(Min([Category]) 
          FOR [Category] IN (' + @ColumnName + ')) AS PVTTable'
--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery

DEMO

Answer 2

你走了：

SELECT id, 

CASE WHEN Category = 'A' THEN 'A' ELSE Null END AS A,
CASE WHEN Category = 'B' THEN 'B' ELSE Null END AS B,
CASE WHEN Category = 'C' THEN 'C' ELSE Null END AS C,
CASE WHEN Category = 'D' THEN 'D' ELSE Null END AS D

FROM Pivot_Check

ORDER BY id;

如何将列值动态地转换为行并在每个列值下显示透视列名？

2 个答案: