tddphoenix_phoenix_doc_example.ex

def update(conn, %{"id" => id, "user" => user_params}) do
  user = Repo.get!(User, id)
  changeset = User.changeset(user, user_params)

  case Repo.update(changeset) do
    {:ok, user} ->
      conn
      |> put_flash(:info, "User updated successfully.")
      |> redirect(to: user_path(conn, :show, user))
    {:error, changeset} ->
      render(conn, "edit.html", user: user, changeset: changeset)
  end
end