Public Class Form1
    Public conn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data" & _
      "Source=Y:\pze.mdb;User Id=admin;Password=;")
 
    Public cmd As New OleDbCommand("Select * from Zeitbuchungen where" & _
      "Z_Pers_Nr=@Nr", conn)
    Public da As New OleDbDataAdapter(cmd)
    Public ds As New DataSet
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
 
        cmd.Parameters.AddWithValue("@Nr", 47)
        da.Fill(ds)    'öffnet und schließt connection von alleine
        DataGridView1.DataSource = ds.Tables(0)
        BenutzerText.Text = "Angemeldeter Benutzer = egal"
 
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        cmd.Parameters.AddWithValue("@Nr", TextBox1.Text)
        da.Fill(ds)    'öffnet und schließt connection von alleine
        DataGridView1.DataSource = ds.Tables(0)
    End Sub
End Class