rails newでアプリを作成したらすること

Rpecの導入

Rpecの導入 - Qiita

Rubocopの導入

Rubocopの導入 - Qiita

データベースのパスワード設定

config/database.yml

# MySQL. Versions 5.5.8 and up are supported.
#
# Install the MySQL driver
#   gem install mysql2
#
# Ensure the MySQL gem is defined in your Gemfile
#   gem "mysql2"
#
# And be sure to use new-style password hashing:
#   https://dev.mysql.com/doc/refman/5.7/en/password-hashing.html
#
default: &default
  adapter: mysql2
  encoding: utf8mb4
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: root
  password: パスワード
  socket: /tmp/mysql.sock

development:
  <<: *default
  database: アプリ名_development

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: アプリ名_test

# As with config/credentials.yml, you never want to store sensitive information,
# like your database password, in your source code. If your source code is
# ever seen by anyone, they now have access to your database.
#
# Instead, provide the password or a full connection URL as an environment
# variable when you boot the app. For example:
#
#   DATABASE_URL="mysql2://myuser:mypass@localhost/somedatabase"
#
# If the connection URL is provided in the special DATABASE_URL environment
# variable, Rails will automatically merge its configuration values on top of
# the values provided in this file. Alternatively, you can specify a connection
# URL environment variable explicitly:
#
#   production:
#     url: <%= ENV["MY_APP_DATABASE_URL"] %>
#
# Read https://guides.rubyonrails.org/configuring.html#configuring-a-database
# for a full overview on how database connection configuration can be specified.
#
production:
  <<: *default
  database: アプリ名_production
  username: アプリ名
  password: パスワード

.gitignoreに以下を追加

.gitignore

/config/database.yml

データベースの作成

ターミナル

$ rails db:create
Created database 'アプリ名_development'
Created database 'アプリ名_test'
$ rails db:migrate
== 20230325044645 CreateUsers: migrating ======================================
-- create_table(:users)
   -> 0.0100s
== 20230325044645 CreateUsers: migrated (0.0101s) =============================

参考記事

• 【Rails入門】mysqlとの接続方法まとめ