#25: Moving to Elixir Part 1

In this series we’ll build a new Phoenix application with data exported from an existing database. This will give us an introduction to moving an existing application to Elixir.

The application we’re going to build is a website for a car dealership. While the site will be fairly straightforward - we’ll get to cover some fundamental parts of Elixir and Phoenix

For example we’ll learn how to map existing database tables and columns to Ecto, define a context, we’ll even get to write a module that imports new inventory using Erlang and Flow.

In this episode we’ll create our repo and load the existing data into a new database.

Let’s get started.

The first thing we need to do is create our new Elixir project.

Let’s go to the command line to create a new project named dealership. Because a new Phoenix app uses Postgres by default and our existing database is MySQL, we’ll need to pass in the database flag with mysql, which sets our new Phoenix app up to use MySQL.

$ mix phx.new dealership --database mysql

And we’ll install the dependencies.

$ Y

Now let’s cd into our new project:

$ cd dealership

And we’ll need to configure our application to use MySQL. Let’s open our dev.exs and make sure our configuration looks good and is updated with your local MySQL details:

config/dev.exs...
# Configure your database
config :dealership, Dealership.Repo,
  adapter: Ecto.Adapters.MySQL,
  username: "root",
  password: "",
  database: "dealership_dev",
  hostname: "localhost",
  pool_size: 10

And then we can create our database:

$ mix ecto.create

With that, let’s start up our server to make sure everything is running.

$ mix phx.server

And great - everything looks good.

Now let’s load our existing database, which you can download here or in the notes above as a file named dealership_course.sql.

Let’s go ahead and import it. I’ll use the MySQL client Sequel Pro - but you can use whatever method you’d like.

And if we inspect what was imported we should see a table named cars with 25 rows loaded.

It looks like everything imported successfully.