Below is the code where you can Filter a row and then update a column value

 	Dim dv As DataView 

	dv = New DataView(ds.Tables(0))
            dv.RowFilter = "PartNum='" & Me.txtParts.Text & "'"
            iCount = dv.Count
            If iCount = 1 Then
                dv(0)("Qty") = Convert.ToInt32(dv(0)("Qty")) + Convert.ToInt32(Me.txtQty.Text)
                gvParts.DataSource = ds
                gvParts.DataBind()
                iCount = 0
                dv = Nothing
                Return
            End If