Dim cn As New OleDb.OleDbConnection("CONN_STRING")
        Dim da As New OleDb.OleDbDataAdapter("SELECT * FROM WIE_AUCH_IMMER", cn)
        Dim cb As New OleDb.OleDbCommandBuilder(da)
        Dim dt As New DataTable("TEST")
        da.Fill(dt)
        da.FillSchema(dt, SchemaType.Source)
        For Each r As DataRow In dt.Rows
            For Each c As DataColumn In dt.Columns
                Debug.WriteLine("Spaltenname: " + c.ColumnName)
                Debug.WriteLine("FeldTyp: " + c.DataType.ToString)
                Debug.WriteLine("Maximale Laenge: " + c.MaxLength) 
                 ' gibt -1 bei nicht TextSpalten zurück
            Next
        Next