Programming Ecto

Chapter 6Making Changes to Your Database

For this last stop on our tour of Ecto, we are going back to the beginning.

In previous chapters, we’ve queried, updated, deleted, and sometimes mangled the dataset that came with our MusicDB app. Now we’re going to take a look at how those tables got created in the first place.

Ecto uses migrations to create and alter tables in your database. A migration is a set of commands, created in Elixir, that contains the instructions for the changes you want to make. Ecto provides mix tasks to help you create, run and even roll back your migrations.

In this chapter, we’ll look at the Ecto.Migration module and work with the tools it provides to help you create and maintain the structure of your database throughout ...