如何使用excel创建参数化查询？ （VB.NET）

Question

我试图使用参数化查询来运行更快的Excel表单中的更新子句......但是当试图做，vb.net说“操作必须使用可更新的查询”。

与串连定期查询，查询的工作原理：

Protected Friend Sub reemplazarDato(ByVal columna As String, ByVal dato As String, ByVal con As String) 
    Dim cmd As String = "" 
    conexion.Open() 
    For Each itm In arrayErrores 
     cmd = "UPDATE [" & obtenerHojaActual(columna, con) & "$] SET [" & columna & "]='" & dato & "' WHERE [" & columna & "]='" & itm & "'" 
     Try 
      Dim comando As New OleDbCommand(cmd, conexion) 
      comando.ExecuteNonQuery() 
      comando.Dispose()    
     Catch ex As Exception 
      repairmanMessage("Error inesperado", ex.Message, My.Resources._error).ShowDialog() 
     End Try 
    Next 
    conexion.Close() 
End Sub 

但是当我尝试这种方式，查询不工作...（“操作必须使用一个可更新的查询”）

Protected Friend Sub reemplazarDato(ByVal columna As String, ByVal dato As String, ByVal con As String) 
    Dim cmd As String = "" 
    Dim hoja As String = obtenerHojaActual(columna, con) 
    Dim comando As New OleDbCommand 
    comando.Connection = conexion 
    conexion.Open() 
    For Each itm In arrayErrores 
     cmd = "UPDATE [" & hoja & "$] SET [@columna]=@dato WHERE [@columna]=@itm" 
     comando.CommandText = cmd 
     comando.Parameters.Add("@columna", OleDbType.VarChar, columna.Length).Value = columna 
     comando.Parameters.Add("@dato", OleDbType.VarChar, dato.Length).Value = dato 
     comando.Parameters.Add("@itm", OleDbType.VarChar, itm.ToString.Length).Value = itm 
     Try 
      comando.ExecuteNonQuery() 
      comando.Parameters.Clear() 
     Catch ex As Exception 
      repairmanMessage("Error inesperado", ex.Message, My.Resources._error).ShowDialog() 
     End Try 
    Next 
    conexion.Close() 
    comando.Dispose() 
End Sub 

我如何用excel来做到这一点？

Answer 1

参数化列名无效 - 即columna需要像在第一个代码块中那样使用字符串连接来设置，而不是作为参数。此外，您不需要为每次迭代定义SQL和命令参数 - 只需定义一次并在每次循环中设置值。

Protected Friend Sub reemplazarDato(ByVal columna As String, ByVal dato As String, ByVal con As String) 
    Dim hoja As String = obtenerHojaActual(columna, con) 
    Dim comando As New OleDbCommand 
    comando.Connection = conexion 
    comando.CommandText = "UPDATE [" & hoja & "$] SET [" & columna & "]=@dato WHERE [" & columna & "]=@itm" 
    comando.Parameters.Add("@dato", OleDbType.VarChar, dato.Length) 
    comando.Parameters.Add("@itm", OleDbType.VarChar, itm.ToString.Length) 
    conexion.Open() 
    For Each itm In arrayErrores 
     comando.Parameters("@dato").Value = dato 
     comando.Parameters("@itm").Value = itm 
     Try 
      comando.ExecuteNonQuery() 
     Catch ex As Exception 
      repairmanMessage("Error inesperado", ex.Message, My.Resources._error).ShowDialog() 
     End Try 
    Next 
    conexion.Close() 
    comando.Dispose() 
End Sub