اظهار الأبناء بعد إختيار الأباء

كود :
Imports System.Data.OleDb



Public Class Form1

    Dim conne As String = "Provider=Microsoft.jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\Database1.mdb"

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        fill_father_name()

    End Sub

    Private Sub fill_father_name()



   Dim SQL As String = "SELECT Fathercode , Fathername From TableFather"

        Dim da As New OleDbDataAdapter(SQL, conne)

        Dim ds As New DataSet

        da.Fill(ds, "TableFather")

        ComboBox1.DataSource = ds.Tables("TableFather")

        ComboBox1.DisplayMember = "Fathername"

        ComboBox1.ValueMember = "Fathercode"

        ComboBox1.SelectedIndex = -1

    End Sub

    Private Sub fill_student_name()

        Dim SQL As String = "SELECT studentname , studentfathercode From TableStudent Where studentfathercode = '" & ComboBox1.SelectedValue & "'"

        Dim da As New OleDbDataAdapter(SQL, conne)

        Dim ds As New DataSet

        da.Fill(ds, "TableStudent")

        ComboBox2.DataSource = ds.Tables("TableStudent")

        ComboBox2.DisplayMember = "studentname"

        ComboBox2.ValueMember = "studentfathercode"

    End Sub

    Private Sub ComboBox1_SelectionChangeCommitted(sender As Object, e As System.EventArgs) Handles ComboBox1.SelectionChangeCommitted

        fill_student_name()

    End Sub



  

End Class