Connecting to a database

So far, we’ve created a Person model and the migrations needed for the structure of our database. Now we are ready to connect to our database. But wait, we’ve already connected to a database! As previously stated, if we were able to run our migration successfully, it means that we did indeed connect to the SQLite database. Now let’s take a look at how Rails is configured to do this. Let’s examine our Gemfile, and in doing so, we’ll see the following line:

…
# Use sqlite3 as the database for Active Record
gem 'sqlite3'
…

The preceding line installs the sqlite3 gem that allows Rails to communicate with a SQLite database. But wait, there’s more. If we open the app/config/database.yml file, we will also see some of the database settings for our project:

…
default: &default
  adapter: sqlite3
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>...