The Repo Module

The heart of Ecto

Now that we’ve got a handle on what a repository is, let’s look at how it’s implemented in Ecto. The Repo module is the heart of Ecto, and just about everything we do will touch Repo somehow. The Repo module is also quite powerful. We can perform all of the classic CRUD operations (create, read, update, and delete) using just the Repo module. The other modules in Ecto make these operations easier, but there’s a lot we can do with Repo.

Repo’s functionality

Given its relationship to the repository pattern, Repo contains many functions, such as get, insert, update, delete, and the like. We never call these functions directly. Instead, we create our own Repo module that lives in the application’s codebase, then integrate Ecto.Repo's functions with Elixir’s use macro. In our sample project lib/music_db/repo.ex, we’ll see the following.