Dim j As Integer
Dim tvwKnoten As TreeNode
Dim abfrage_cmd As OleDb.OleDbCommand
Dim abfrage_reader As OleDb.OleDbDataReader
Dim abfrage_reader2 As OleDb.OleDbDataReader
Dim firma As String
Dim KND_ID As Integer
Dim Drucker As String
 
        TreeView1.Nodes.Clear()
        With TreeView1
            .CheckBoxes = False
            .ShowLines = True
            .ShowPlusMinus = True
            .ShowRootLines = True
        End With
 
        test.Open()
        abfrage_cmd = New OleDb.OleDbCommand("SELECT Firma, ID FROM tbl_kunde" & _
          "ORDER BY Firma ASC", test)
        abfrage_reader = abfrage_cmd.ExecuteReader
        tvwKnoten = TreeView1.Nodes.Add("Kundenstamm")
        Dim neuerKnoten As TreeNode
        Try
            While abfrage_reader.Read()
                firma = abfrage_reader(0)
                KND_ID = abfrage_reader(1)
                neuerKnoten = tvwKnoten.Nodes.Add(firma)
                'test.Close()
                test2.Open()
                abfrage_cmd = New OleDb.OleDbCommand("SELECT Modell FROM" & _
                  "tbl_drucker WHERE Kunden_ID = " & KND_ID & " ", test2)
                abfrage_reader2 = abfrage_cmd.ExecuteReader
                While abfrage_reader2.Read
                    Drucker = abfrage_reader2(0)
                    neuerKnoten.Nodes.Add(Drucker)
                End While
                test2.Close()
            End While
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        TreeView1.Select()
        TreeView1.SelectedNode = TreeView1.Nodes(0)