Insert multivalues itmes checkedlistbox into single field access

<pre> Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try
            'CheckedListBox1.Show()
            DateTimePicker1.Value = Date.Now



            'Dim cmd As New OleDbCommand


            Dim cmd As OleDbCommand = New OleDbCommand("select * from dossier_ass where pieces_fourni =@pieces_fourni and pieces_manquant = @pieces_manquant", cn)
            Dim da As New OleDbDataAdapter(cmd)
            Dim dt As New DataTable()
            Dim pieces_fourni As String = ""
            Dim pieces_manquant As String = ""
            cmd.Parameters.AddWithValue("@pieces_fourni", pieces_fourni)
            cmd.Parameters.AddWithValue("@pieces_manquant", pieces_manquant)
            
            cn.Open()

            cmd = New OleDbCommand("Insert into tab_asso (id_dossier,denomination,date_recep,nom_prenom,adresse,wilaya,code_wilaya,region,pieces_fourni,pieces_manquant) VALUES(@id_dossier,@denomination,@date_recep,@nom_prenom,@adresse,@wilaya,@code_wilaya,@region,@pieces_fourni,@pieces_manquant) ", cn)
            cmd.Parameters.AddWithValue("@id_dossier", TextBox1.Text)
            cmd.Parameters.AddWithValue("@denomination", TextBox2.Text)
            cmd.Parameters.AddWithValue("@date_recep", DateTimePicker1.Text)
            cmd.Parameters.AddWithValue("@nom_prenom", TextBox6.Text)
            cmd.Parameters.AddWithValue("@adresse", TextBox7.Text)
            cmd.Parameters.AddWithValue("@wilaya", ComboBox1.Text)
            cmd.Parameters.AddWithValue("@code_wilaya", TextBox4.Text)
            cmd.Parameters.AddWithValue("@Region", TextBox5.Text)
            For Each dr As DataRow In dt.Rows
                Dim selectedIndex As Integer = CheckedListBox1.SelectedIndex
                If selectedIndex <> -1 Then
                    'Loop through items to get their check states.
                    For i As Integer = 0 To CheckedListBox1.Items.Count - 1
                        Dim checkstate As CheckState
                        checkstate = CheckedListBox1.GetItemCheckState(i)
                        If (checkstate = checkstate.Checked) Then
                            
                            cmd.Parameters.AddWithValue("@pieces_fourni", CheckedListBox1.Items(i)).ToString() 'true
                        Else
                            
                            cmd.Parameters.AddWithValue("@pieces_manquant", CheckedListBox1.Items(i)).ToString() 'false

                        End If
                    Next
                End If
            Next

            cmd.ExecuteNonQuery()
        Catch ex As Exception
            MessageBox.Show("Erreur lors de l'insertion de l'enregistrement dans la table..." & ex.Message, "Insértion d'Enregistrement")
        Finally
            cn.Close()
            refraiche()
        End Try
        MessageBox.Show("Données insérées avec succès")

    End Sub