Imports System.Data.OleDb
 
Public Class Form1
    Dim connStr As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data" & _
      "Source=db_docma.mdb;"
    Dim conn As New OleDbConnection(connStr)
 
 
    Dim selStr As String = "SELECT KundenCode, Vorname, Nachname FROM Kunden"
    Dim da As New OleDbDataAdapter(selStr, conn)
    Dim ds As New DataSet()
 
 
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
 
 
        Try
            conn.Open()
            da.Fill(ds, "Kunden")
 
            ' Die Tabelle Material wird geladen:
            selStr = "SELECT Material.MaterialNr, Material.KundenCode," & _
                     " Material.Bestellnummer, Material.Lieferant," & _
                     "Material.Beschreibung" & _
                     " FROM Kunden, Material WHERE (Kunden.KundenCode =" & _
                     "Material.KundenCode)"
            da = New OleDbDataAdapter(selStr, conn)
            da.Fill(ds, "Bestellungen")
 
            conn.Close()
 
            ' Die DataRelation wird zum DataSet hinzugefügt:
            ds.Relations.Add("KundenMaterial", ds.Tables("Kunden").Columns( _
              "KundenCode"), _
                                                ds.Tables( _
                                                "Bestellungen").Columns( _
                                                "KundenCode"))
            ' Anbinden des DataGrid:
            DataGrid1.SetDataBinding(ds, "Kunden")
 
 
        Catch ex As Exception
            MessageBox.Show(ex.Message, "Fehler beim öffnen der Datenbank !")
 
        End Try
        conn.Close()
    End Sub
 
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
 
        Dim cmd As New OleDbCommand("UPDATE Kunden SET * = WHERE KundenCode =" & _
          "?", conn)
        cmd.Parameters.Add("@p1", OleDbType.VarChar, 30, "Nachname")
 
        'Schlüsselspalte
        Dim prm As OleDbParameter = cmd.Parameters.Add("@p2", OleDbType.VarChar)
        prm.SourceColumn = "KundenCode"
 
        prm.SourceVersion = DataRowVersion.Original
 
        da.UpdateCommand = cmd
        da.Update(ds, "Kunden")
 
    End Sub
End Class