public sub CheckDB()
  Dim adap as New SqlDataAdapter( "SELECT * from TabellenName", _
    Connectionstring )
  Dim cb as New SqlCommandBuilder(Adap)
  Dim dt as New DataTable()
 
  Try
    adap.Fill( dt )
    dt.Rows[0][1] = IrgendEinPassenderWert
    adap.Update(dt)
  Catch ex as Exception
    MessageBox.Show( ex.ToString())
  End Try
End Sub