เขียนโปรแกรมแก้ไขข้อมูลแล้ว error ว่า ArgumentException was unhandled / Column 'Product_ID' does not belong to table sa. และอยากรู้เรื่อง Crystal reports ด้วยคับ

Dim sql3 As String = "SELECT * FROM TblSale_on_Cash WHERE Cash_ID = " & a
            Dim cmd3 As New OleDbCommand(sql, conn)
            Dim adapter3 As New OleDbDataAdapter(cmd)
            Dim data3 As New DataSet
            adapter3.Fill(data3, "sa")

            For count = 0 To data3.Tables(0).Rows.Count - 1

               [color=yellow] Dim sql5 As String = "SELECT * FROM TblProduct WHERE Product_ID = " & data3.Tables("sa").Rows(count)("Product_ID")
                Dim cmd5 As New OleDbCommand(sql5, conn)
                Dim adapter5 As New OleDbDataAdapter(cmd5)
                Dim data5 As New DataSet
                adapter5.Fill(data5, "pro")

                Dim Sql4 As String = "UPDATE TblProduct SET Stock = @a WHERE Product_ID = " & data3.Tables("sa").Rows(count)("Product_ID")
                Dim cmd4 As New OleDbCommand(Sql4, conn)
                cmd4.Parameters.AddWithValue("a", data5.Tables("product").Rows(0)("Stock") + data3.Tables("sa").Rows(count)("Amount"))
                cmd4.ExecuteNonQuery()
            Next