Question

所以我有这段代码

               Using FileObject As New FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None)
                    Using StreamWriterObj As New StreamWriter(FileObject)
                        connect.Open()
                        Using reader As SqlDataReader = command.ExecuteReader()
                            Dim FieldCount As Integer = reader.FieldCount - 1
                            Do While reader.Read()
                                StreamWriterObj.Write(reader.Item(0))
                                For i = 1 To FieldCount
                                    StreamWriterObj.Write(" @ ")
                                    StreamWriterObj.Write(reader.Item(i))
                                Next
                                StreamWriterObj.WriteLine()
                            Loop
                        End Using
                        connect.Close()
                    End Using
                End Using

它基本上将我的SQL查询结果设置为StreamWriter对象并将其导出为.txt文件。以下是选择查询后的结果示例：

+---------------------------------------+
|                Results                |
+---------------------------------------+
+                                       +
| Document No.|   #   |  col 3 |  col 4 |
+-------------+-------+--------+--------+
| 333456      |   0   | "value"| "value"|
+-------------+-------+--------+--------+
| 333456      |   0   | "value"| "value"|
+-------------+-------+--------+--------+
| 462345      |   0   | "value"| "value"|
+-------------+-------+--------+--------+
| 585357      |   0   | "value"| "value"|
+-------------+-------+--------+--------+

所以我的任务是以这样的方式制作它，当我导出到.txt文件时，里面会看起来像这样：

+---------------------------------------+
|                Results                |
+---------------------------------------+
+                                       +
| Document No.|   #   |  col 3 |  col 4 |
+-------------+-------+--------+--------+
| 333456      |   1   | "value"| "value"|
+-------------+-------+--------+--------+
| 333456      |   2   | "value"| "value"|
+-------------+-------+--------+--------+
| 333456      |   3   | "value"| "value"|
+-------------+-------+--------+--------+
| 462345      |   1   | "value"| "value"|
+-------------+-------+--------+--------+
| 585357      |   1   | "value"| "value"|
+-------------+-------+--------+--------+
| 585357      |   2   | "value"| "value"|
+-------------+-------+--------+--------+

或者换句话说，根据文档号来计算（下一个数字）行。（选择查询按文档编号排序）。

我认为一个明智的解决方案是使用StringBuilder，但我需要一些帮助。

谢谢

Answer 1

id在实际的sql中执行： -

WITH
  q AS
(select query)
,
sequenced as (
  SELECT
    ROW_NUMBER() OVER (PARTITION BY [Document no. Column] ORDER BY [column name] 
 ) AS sequence_id,
    *
 FROM
    q
)
SELECT
*
FROM
  sequenced

如何计算（1,2,3 ......）我的DataReader结果

1 个答案: