'Grid füllen
        Dim da As New MySqlDataAdapter(sql, conn)
        Dim ds As New DataSet
        da.Fill(ds)
        For Each c As DataColumn In ds.Tables(0).Columns
            If c.ColumnName = "Entfernung" Or c.ColumnName = "Fahrzeit" Then _
              c.DataType = System.Type.GetType("System.String")
        Next
        Dim dv As New DataView(ds.Tables(0))
        dgvData.DataSource = dv