如何从行中选择数据并使用存储过程将其显示为列？

CREATE TABLE RowData (
    Id INT PRIMARY KEY,
    Data1 VARCHAR(50),
    Data2 VARCHAR(50),
    Data3 VARCHAR(50)
)

INSERT INTO RowData (Id, Data1, Data2, Data3)
VALUES (1, 'A', 'B', 'C'),
       (2, 'D', 'E', 'F'),
       (3, 'G', 'H', 'I')

CREATE PROCEDURE ConvertToColumns
AS
BEGIN
    DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
    DECLARE @ColumnNames AS NVARCHAR(MAX)

    -- 构建列名
    SELECT @ColumnNames = COALESCE(@ColumnNames + ', ', '') + QUOTENAME(DataColumn)
    FROM (SELECT DISTINCT DataColumn FROM RowData) AS Temp

    -- 构建动态Pivot查询
    SET @DynamicPivotQuery = N'
    SELECT *
    FROM (
        SELECT Id, DataColumn, DataValue
        FROM RowData
        CROSS APPLY (
            VALUES (''Data1'', Data1),
                   (''Data2'', Data2),
                   (''Data3'', Data3)
        ) AS CA(DataColumn, DataValue)
    ) AS PivotData
    PIVOT (
        MAX(DataValue)
        FOR DataColumn IN (' + @ColumnNames + ')
    ) AS PivotResult'

    -- 执行动态Pivot查询
    EXEC sp_executesql @DynamicPivotQuery
END

EXEC ConvertToColumns

Id | Data1 | Data2 | Data3
---+-------+-------+-------
 1 | A     | B     | C
 2 | D     | E     | F
 3 | G     | H     | I