Dim DADatei As New OleDbDataAdapter("SELECT tCheck, DateiID, Titel ....FROM" & _
  "TDatei WHERE KatID=" & tmpID & "", MyConn)
Dim DTDatei As New DataTable
 
        Try
            MyConn.Open()
            DADatei.Fill(DTDatei)
        Catch ex As Exception
            MessageBox.Show(ex.Message, "Fehler", MessageBoxButtons.OK, _
              MessageBoxIcon.Exclamation)
        Finally
            MyConn.Close()
        End Try
 
        TDateiDataGridView.DataSource = DTDatei
        With Me.TDateiDataGridView
            .Columns("DateiID").HeaderText = "Dat-Nr."
            .AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill
            .SelectionMode = DataGridViewSelectionMode.FullRowSelect
            .MultiSelect = False
        End With

~ no brain, no headache ~