An Elixir model for basic db functionality, to be brief.

rich_model.ex

defmodule RichModel do
@moduledoc """
  A mini-package that injects basic db functionality in any model. 
  Good for rapid prototyping.
"""

defmacro __using__([]) do # alternatively, `defmacro __using__([repo: repo]) do ....`
  quote do
    alias __BASE_MODULE__.Repo # __BASE_MODULE__ is the app root name

    def get(id, _preload \\ true), do: Repo.get(__MODULE__, id)
    def get!(id), do: Repo.get!(__MODULE__, id)
    def list(), do: Repo.all(__MODULE__)
    def count(), do: Repo.aggregate(__MODULE__, :count, :id)

    def get_by(opts), do: Repo.get_by(__MODULE__, opts)
    def get_by!(opts), do: Repo.get_by!(__MODULE__, opts)

    def create(attrs) do
      %__MODULE__{}
      |> __MODULE__.changeset(attrs)
      |> Repo.insert()
    end

    def create!(attrs) do
      %__MODULE__{}
      |> __MODULE__.changeset(attrs)
      |> Repo.insert!()
    end

    def update(item = %__MODULE__{}, attrs) do
      item
      |> __MODULE__.changeset(attrs)
      |> Repo.update()
    end

    def update!(item = %__MODULE__{}, attrs) do
      item
      |> __MODULE__.changeset(attrs)
      |> Repo.update!()
    end

    defoverridable get: 2, list: 0, create: 1, create!: 1, update: 2, update!: 2

    import Ecto.Query

    def list_all_by(field_name, value) do
      from(t in __MODULE__, where: field(t, ^field_name) == ^value)
      |> Repo.all()
    end
  end
end