Почему мой запрос на обновление не работает ?

---

Private Sub updateww()
        Dim con As New SqlConnection
        Dim cmd As New SqlCommand

        con.ConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Administrator\Documents\Visual Studio 2010\Projects\St. Peter Academy\St. Peter Academy\App_Data\St.mdf;Integrated Security=True;User Instance=True"
        con.Open()
        cmd.Connection = con
        cmd.CommandText = "update " & dbname.Text & " set percentage='" & edwwp.Text & "', description='" & edwwd.Text & "' where componentid=1 "
        cmd.ExecuteNonQuery()
        con.Close()

    End Sub

    Private Sub updatept()
        Dim con As New SqlConnection
        Dim cmd As New SqlCommand

        con.ConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Administrator\Documents\Visual Studio 2010\Projects\St. Peter Academy\St. Peter Academy\App_Data\St.mdf;Integrated Security=True;User Instance=True"
        con.Open()
        cmd.Connection = con
        cmd.CommandText = "update " & dbname.Text & " set percentage= '" & edptp.Text & "', description='" & edptd.Text & "' where componentid=2 "
        cmd.ExecuteNonQuery()
        con.Close()

    End Sub
    Private Sub updateqa()
        Dim con As New SqlConnection
        Dim cmd As New SqlCommand

        con.ConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Administrator\Documents\Visual Studio 2010\Projects\St. Peter Academy\St. Peter Academy\App_Data\St.mdf;Integrated Security=True;User Instance=True"
        con.Open()
        cmd.Connection = con
        cmd.CommandText = "update " & dbname.Text & " set percentage='" & edqap.Text & "', description='" & edqad.Text & "' where componentid=3 "
        cmd.ExecuteNonQuery()
        con.Close()

    End Sub

Что я уже пробовал:

мое обновление не работает . он не показывает никаких ошибок, но не обновляется

---