Imports System.Data
Imports System.Data.OleDb
 
Public Class Form1
    Dim ConnString As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
        "Data Source=C:\MeineDB.mdb"
    Dim oConn As New OleDbConnection(ConnString)
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
 
    End Sub
 
    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles TextBox1.TextChanged
 
 
 
        ' Prüfen ob es sich nur um Zahlen handelt( Barcode)  
        If IsNumeric(TextBox1.Text) = False Then
            msgbox("Nur Zahlen sind erlaubt")
            Exit Sub
        End If
 
       'Öffnen der Datenbank
        oConn.Open()
        Dim MyDataReader As OleDbDataReader
 
        Dim oCommand As New OleDbCommand("SELECT Artikel FROM Tab_Barcode WHERE" & _
          "Barcode=" & TextBox1.Text)
 
        oCommand.Connection = oConn
 
        MyDataReader = oCommand.ExecuteReader
 
        With MyDataReader
            Do While .Read()
                TextBox2.Text = .Item("Artikel")
 
            Loop
        End With
        oCommand.Dispose()
 
        oConn.Close() ' Wichtig schließen der DB, sonst droht Exeption
End Sub
End Class