schema "post" do
    field :name, :string
    field :description, :string
    field :inserted_at, Ecto.DateTime, default: Ecto.DateTime.local
    field :updated_at, Ecto.DateTime, default: Ecto.DateTime.local
  end

  before_insert :add_creation_timestamp
  before_update :update_updated_timestamp

  def add_creation_timestamp(changeset) do
    changes = %{changeset.changes | inserted_at: Ecto.DateTime.local, updated_at: Ecto.DateTime.local}
    %Ecto.Changeset{changeset | changes: changes}
  end

  def update_updated_timestamp(changeset) do
    changes = %{changeset.changes | updated_at: Ecto.DateTime.local}
    %Ecto.Changeset{changeset | changes: changes}
  end