Adding Multiple Datagridviewcomboboxcolumn in datagridview

Public Class Form1
    Dim mcn As MySqlConnection
    Dim mcm As MySqlCommand
    Dim mda As New MySqlDataAdapter
    Dim mdt As New DataTable
    Dim mds As New DataSet
    Dim str As String
    Dim value As String

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        str = "server=localhost;uid=root;pwd=bss;database=cdetail"
        mcn = New MySqlConnection
        mcn.ConnectionString = str
        mcn.Open()
        FillGridView()

        End Sub

    Private Sub FillGridView()

        '--- Adding the values into the combo box through the List---
        Dim cmbOpt1 As DataGridViewComboBoxColumn = CType(DataGridView1.Columns("loc"), DataGridViewComboBoxColumn)
        Dim cmbOpt2 As DataGridViewComboBoxColumn = CType(DataGridView1.Columns("PRODUCT"), DataGridViewComboBoxColumn)
        Try

            str = "select Name,fullname from others order by Name"
            mda = New MySqlDataAdapter(str, mcn)
            Dim mdt1 As New DataTable
            mda.Fill(mdt1)
            'If loc.DataSource Is Nothing Then
            cmbOpt1.DataSource = mdt1
            cmbOpt1.DisplayMember = "Name"
            cmbOpt1.ValueMember = "fullname"

            Dim str2 As String
            Dim mda1 As New MySqlDataAdapter
            Dim mdt2 As New DataTable
            str2 = "select productname,fullname from product order by productname"
            mda = New MySqlDataAdapter(str2, mcn)
            mda.Fill(mdt2)
            cmbOpt2.DataSource = mdt2
            cmbOpt2.DisplayMember = "productname"
            cmbOpt2.ValueMember = "fullname"

        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

    End Sub

End Class