Question

我想将行转换为列。

Column1 Column2    Column3     Column4  Column5 Column6 Column7
 1      2016-07-25  7           3        c1      c11    c111
 2      2016-07-26  5           2        c2      c22    c222
 3      2016-07-27  1           2        c3      c33    c333
 4      2016-07-28  3           1        c4      c44    c444

我想要输出如下：

Column1        1            2         3           4
Column2    2016-07-25    2016-07-26  2016-07-27  2016-07-28
Column3        7            5         1           3
Column4        3            2         2           1
Column5       c1            c2       c3          c4
Column6       c11           c22      c33         c44
Column7       c111          c222     c333        c44

我尝试使用pivot unpivot但是没有找到合适的解决方案。第一个表（输入）可以有n行。

Answer 1

我尝试使用pivot unpivot但是没有找到合适的解决方案。第一个表（输入）可以有n行。

它不起作用的原因是因为PIVOT不适用于动态行数。这意味着语法只能将固定数量的行转换为列，您需要在查询中指定它。它无法根据行中的值动态自动生成列。

修改

我发现动态支点的一个解决方案（谷歌搜索的第一个结果）：https://www.mssqltips.com/sqlservertip/2783/script-to-create-dynamic-pivot-queries-in-sql-server/

它需要动态SQL（没有其他选项）

Answer 2

你需要使用UNPIVOT，然后是PIVOT，如果列号未知 - 动态SQL：

DECLARE @columns nvarchar(max), 
        @columns_with_convert nvarchar(max),
        @row_numbers nvarchar(max),
        @sql nvarchar(max)

SELECT @columns = STUFF((
SELECT ','+QUOTENAME(name)
FROM sys.columns
WHERE [object_id] = OBJECT_ID('##YourTable')
FOR XML PATH('')),1,1,'')
--Will get you [Column1],[Column2],[Column3],[Column4],[Column5],[Column6],[Column7]

SELECT @columns_with_convert = (
SELECT 'CAST('+QUOTENAME(name)+' as nvarchar(max)) as '+QUOTENAME(name) +','
FROM sys.columns
WHERE [object_id] = OBJECT_ID('##YourTable')
FOR XML PATH(''))
--Will get you CAST([Column1] as nvarchar(max)) as [Column1], ... because all rows must be same datatype.

SELECT @row_numbers = STUFF((
SELECT ','+ QUOTENAME(CAST(ROW_NUMBER() OVER (ORDER BY (SELECT 1)) as nvarchar(max)))
FROM ##YourTable
FOR XML PATH('')),1,1,'')
--This will be used when PIVOTing ([1],[2],[3],[4])

SELECT @sql = '
SELECT *
FROM (
    SELECT  RN, 
            [Columns],
            [Values]
    FROM (
        SELECT  '+@columns_with_convert+'
                ROW_NUMBER() OVER (ORDER BY (SELECT 1)) as RN
        FROM ##YourTable
        ) as p
    UNPIVOT (
        [Values] FOR [Columns] IN ('+@columns+')
    ) as unpvt
) as s
PIVOT (
    MAX([Values]) FOR RN IN ('+@row_numbers+')
) as pvt
'

EXEC sp_executesql @sql

输出：

Columns 1           2           3           4
Column1 1           2           3           4
Column2 2016-07-25  2016-07-26  2016-07-27  2016-07-28
Column3 7           5           1           3
Column4 3           2           2           1
Column5 c1          c2          c3          c4
Column6 c11         c22         c33         c44
Column7 c111        c222        c333        c444

如果您PRINT @sql，您将收到查询文字：

SELECT *
FROM (
    SELECT  RN, 
            [Columns],
            [Values]
    FROM (
        SELECT  CAST([Column1] as nvarchar(max)) as [Column1],CAST([Column2] as nvarchar(max)) as [Column2],CAST([Column3] as nvarchar(max)) as [Column3],CAST([Column4] as nvarchar(max)) as [Column4],CAST([Column5] as nvarchar(max)) as [Column5],CAST([Column6] as nvarchar(max)) as [Column6],CAST([Column7] as nvarchar(max)) as [Column7],
                ROW_NUMBER() OVER (ORDER BY (SELECT 1)) as RN
        FROM ##YourTable
        ) as p
    UNPIVOT (
        [Values] FOR [Columns] IN ([Column1],[Column2],[Column3],[Column4],[Column5],[Column6],[Column7])
    ) as unpvt
) as s
PIVOT (
    MAX([Values]) FOR RN IN ([1],[2],[3],[4])
) as pvt

Answer 3

DECLARE @TABLE TABLE 
   (RowNo INT,Col1 VARCHAR(10),Col2 VARCHAR(10)
   ,Col3 VARCHAR(10))      
INSERT INTO @TABLE VALUES 
   (1,'A','B','C')
SELECT Kishore from @Table
Unpivot(Kishore For Value IN (Col1,Col2,Col3)) AS H

将行转换为sql server列

3 个答案: