Imports System.Data.OleDb
 
Public Class Form1
    Dim con As New OleDbConnection
    Dim cmd As New OleDbCommand
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        con.ConnectionString =
        "Provider=Microsoft.Jet.OLEDB.4.0;" &
        "Data Source=C:\Faktu_VB2013\datenbank\faktur.mdb;"
    End Sub
 
    Private Sub txtKdnr_TextChanged(sender As Object, e As EventArgs) Handles _
      txtKdnr.TextChanged
        If Len(txtKdnr.Text) = 6 Then
 
            cmd.Connection = con
            cmd.CommandText = "select kdnr, name, plz, ort from stammdat where" & _
              "kdnr = " &  txtKdnr.Text
            con.Open()
            cmd.ExecuteReader()
        End If
    End Sub
End Class