Question

我的Microsoft SQL服务器中有以下表格。我想将行转换为列。

我的问题是我不知道前面的结果，可能有超过3行在结果中。

当前表格

ID - Function - Result - MasterKey
1  - 100      - 31     - 7
1  - 125      - 34     - 7
1  - 138      - 39     - 7
.  - .        - .      - .
.  - .        - .      - .

期望的结果

MasterKey - Function1 - Result1 - Function2 - Result2 - Function3 - Result3 - ...
7         - 100       - 31      - 125       - 34      - 138       - 39      - ...

我怎样才能实现它？提前谢谢。

Answer 1

如果您有未知数量的函数/结果，则需要动态创建SQL：

DECLARE @SQL NVARCHAR(MAX) = '';

SET @SQL = 'SELECT MasterKey' + 
            (   SELECT  ', Function' + RowNum + ' = MAX(CASE WHEN RowNumber = ' + RowNum + ' THEN [Function] END)' + 
                        ', Result' + RowNum + ' = MAX(CASE WHEN RowNumber = ' + RowNum + ' THEN Result END)'
                FROM    (   SELECT  DISTINCT 
                                    RowNum = CAST(ROW_NUMBER() OVER (PARTITION BY MasterKey 
                                                                        ORDER BY [Function]) 
                                                    AS VARCHAR(10))
                            FROM    T
                        ) t
                FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') + 
            ' FROM (SELECT MasterKey, [Function], Result, RowNumber = ROW_NUMBER() OVER (PARTITION BY MasterKey ORDER BY [Function]) FROM T) AS T GROUP BY MasterKey';

EXECUTE sp_executesql @sql;

<强> Example on SQL Fiddle

在SQL中动态地将行转换为列

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