Question

美好的一天，

我开发了一款管理运动计时的应用程序。我在Visual Studio 2013和MySQL 5.6，我使用的语言和数据库方面经验丰富。我已经广泛尝试通过阅读遇到的类似错误来解决我的问题。

我在MySQL DB中有一个表要导出到.csv文件，但是当我以编程方式执行该语句时，我收到“命令执行期间遇到致命错误”错误消息。

我将SQL命令打印到MsgBox，在MySQL Workbench中复制并粘贴命令，命令执行正常并创建.csv文件。任何帮助解决这个问题将不胜感激。

这是我的代码：

Private Sub FullSetToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FullSetToolStripMenuItem.Click
  Dim ExportQuery, SqlQuery As String
  Dim Comm As New MySqlCommand

  With sfdExportResults
   .InitialDirectory = "C:\Users\"
   .Title = "Export CSV Files"
   .CheckPathExists = True
   .DefaultExt = "csv"
   .Filter = "CSV files (*.csv)|*.csv|All files (*.*)|*.*"
   .FilterIndex = 1
   .FileName = Me.EventCode
   .ShowDialog()
  End With

  FullSetPath = Replace(FullSetPath, "\", "/")
  ExportQuery = "select 'racetime." & Me.EventCode & "' into @tableName; " _
                & "select """ & FullSetPath & """ into @outputFile; " _
                & "select group_concat(concat(""'"",column_name, ""'"")) " _
                & "into @columnNames from information_schema.columns where table_name=@tableName;" _
                & "SET @query = CONCAT(""select * from ((SELECT "",@columnNames,"") UNION (SELECT * FROM '"",@tableName,""')) " _
                & "as a INTO OUTFILE '"", @outputFile, ""' FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n'""); " _
                & "PREPARE stmt FROM @query; " _
                & "EXECUTE stmt;"

    MsgBox(ExportQuery)
    MsgBox(FullSetPath)
    Try
        Comm.Connection = Conn
        Comm.CommandText = ExportQuery
        Comm.ExecuteScalar()
        MsgBox("CSV successfully exported to: " & FullSetPath)
    Catch MySqlCmdExeError As MySqlException
        MsgBox("Error exporting CSV file: " & MySqlCmdExeError.Message)
    End Try
End Sub

在MySQL Workbench中成功执行的软件生成的命令文本：

选择'racetime.DD0010'INTO @tableName; 选择“C：/Users/Peter/Desktop/DD0010.csv”INTO @outputFile; SELECT group_concat（concat（“'”，column_name，“'”））INTO @columnNames FROM information_schema.columns WHERE table_name = @ tableName; SET @query = CONCAT（“SELECT * FROM（（SELECT”，@ columnNames，“）UNION（SELECT * FROM'”，@ tableName，“'））AS INTO OUTFILE'”，@ outputfile，“'FIELDS TERMINATED BY '，'由'\ n''终止的线条;）; 准备stmt FROM @query; 执行stmt;

我之前成功使用了另一个创建.csv文件的命令，但没有列标题，因此我在上面构造的新命令给出了错误。上一个工作命令：

ExportQuery= "SELECT * FROM " & Me.EventCode & " INTO OUTFILE """ & FullSetPath & """ FIELDS TERMINATED BY ',';"  'LINES TERMINATED BY '\n'

提前感谢您的帮助。

在Visual Studio 2013中执行MySQL命令期间遇到致命错误

0 个答案: