How to Insert record in DataGridView

Public Class Entry_data
    Dim baris, kolom As Integer
    Dim data1, data2, data3, data4 As String


    Private Sub DG1_CellClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DG1.CellClick
        baris = DG1.CurrentRow.Index
        If DG1.Columns(e.ColumnIndex).Name = "Kode Barang" Then
            kolom = 1
        Else
            If DG1.Columns(e.ColumnIndex).Name = "Nama Barang" Then
                kolom = 2
            Else
                If DG1.Columns(e.ColumnIndex).Name = "Satuan" Then
                    kolom = 3
                Else
                    kolom = 4
                   
                End If
                End If
            End If

    End Sub
    Private Sub simpan()
        If kolom = 1 Then
            Tampil.Connection = Dtbase
            Tampil.CommandType = CommandType.Text
            Tampil.CommandText = "insert into Barang (kdbrg) values ( '" & Trim(data1) & "')"
            Tampil.ExecuteNonQuery()
        Else
            If kolom = 2 Then
                Tampil.Connection = Dtbase
                Tampil.CommandType = CommandType.Text
                Tampil.CommandText = "update Barang set nmbrg='" & Trim(data2) & "'where kdbrg='" & Trim(data1) & "'"
                Tampil.ExecuteNonQuery()
            Else
                If kolom = 3 Then
                    Tampil.Connection = Dtbase
                    Tampil.CommandType = CommandType.Text
                    Tampil.CommandText = "update Barang set satuan='" & Trim(data3) & "'where kdbrg='" & Trim(data1) & "'"
                    Tampil.ExecuteNonQuery()
                End If
                If kolom = 4 Then
                    Tampil.Connection = Dtbase
                    Tampil.CommandType = CommandType.Text
                    Tampil.CommandText = "update Barang set harga='" & Trim(data4) & "'where kdbrg='" & Trim(data1) & "'"
                    Tampil.ExecuteNonQuery()
                End If
            End If
        End If
    End Sub

    Private Sub DG1_CellValueChanged(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DG1.CellValueChanged
        'untuk mengambil nilai dari cell
        If IsDBNull(DG1.Item(0, baris).Value) Then
        Else
            data1 = DG1.Item(0, baris).Value

        End If
        If IsDBNull(DG1.Item(1, baris).Value) Then
        Else
            data2 = DG1.Item(1, baris).Value
        End If
        If IsDBNull(DG1.Item(2, baris).Value) Then
        Else
            data3 = DG1.Item(2, baris).Value
        End If
        If IsDBNull(DG1.Item(3, baris).Value) Then
        Else
            data4 = DG1.Item(3, baris).Value
        End If
        Call simpan()


    End Sub

    Private Sub Entry_data_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Call koneksi()
        Call isiDG11()


    End Sub
    Private Sub isiDG11()
        DS = New DataSet

        Tabel = "select kdbrg as [Kode Barang],nmbrg as [Nama Barang],satuan as [Satuan],harga as [Harga] FROM Barang "

        '"SELECT Pembayaran.no_ktw, Pembayaran.npm, Pembayaran.semester FROM Pembayaran"
        Grid = New OleDb.OleDbDataAdapter(Tabel, Dtbase)
        Grid.Fill(DS, "Barang")

        Dim Gridview As New DataView(DS.Tables("Barang"))
        DG1.DataSource = Gridview
        DG1.Columns(0).Width = 150 'untuk menentukan lebar kolom
        DG1.Columns(1).Width = 150
        DG1.Columns(2).Width = 100
        DG1.Columns(3).Width = 100

    End Sub
End Class