Programming Ecto

Creating Your Repo Module

Next we need to create our app’s repository module. We went through this process in detail in Chapter 1, ​Getting Started with Repo​ but we’ll run through it again here.

Open a new file called lib/my_app/repo.ex and add the following:

defmodule MyApp.Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Ecto.Adapters.Postgres
end

The use Ecto.Repo directive will make our module a bona fide Ecto repository—all of Ecto’s repository functions will be defined and made available on this module. For more details on how this works, see ​The Repo Module​.

The otp_app: :my_app option tells Ecto where to find the repository configuration. So far, our project only has the my_app application, ...