railsサーバーを立ち上げ時のActiverRecordエラー

Question

前提・実現したいこと

Railsチュートリアルに沿って勉強しており、今Cloud9上でサーバーを立ち上げようとしています。
下記のエラーメッセージが表示され、いくつかの手段を実行したもののエラーを解消できずにいるので
ご教示いただきたいです。

発生している問題・エラーメッセージ

ActiveRecord::ConnectionNotEstablished
No connection pool with 'primary' found.

該当のソースコード

activerecord (6.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:1107:in `retrieve_connection'
activerecord (6.0.0) lib/active_record/connection_handling.rb:231:in `retrieve_connection'
activerecord (6.0.0) lib/active_record/connection_handling.rb:199:in `connection'
activerecord (6.0.0) lib/active_record/migration.rb:562:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
activesupport (6.0.0) lib/active_support/callbacks.rb:101:in `run_callbacks'
actionpack (6.0.0) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/actionable_exceptions.rb:17:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:32:in `call'
web-console (3.3.0) lib/web_console/middleware.rb:131:in `call_app'
web-console (3.3.0) lib/web_console/middleware.rb:20:in `block in call'
web-console (3.3.0) lib/web_console/middleware.rb:18:in `catch'
web-console (3.3.0) lib/web_console/middleware.rb:18:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
railties (6.0.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (6.0.0) lib/rails/rack/logger.rb:26:in `block in call'
activesupport (6.0.0) lib/active_support/tagged_logging.rb:80:in `block in tagged'
activesupport (6.0.0) lib/active_support/tagged_logging.rb:28:in `tagged'
activesupport (6.0.0) lib/active_support/tagged_logging.rb:80:in `tagged'
railties (6.0.0) lib/rails/rack/logger.rb:26:in `call'
sprockets-rails (3.2.1) lib/sprockets/rails/quiet_assets.rb:13:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/request_id.rb:27:in `call'
rack (2.0.7) lib/rack/method_override.rb:22:in `call'
rack (2.0.7) lib/rack/runtime.rb:22:in `call'
activesupport (6.0.0) lib/active_support/cache/strategy/local_cache_middleware.rb:29:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/static.rb:126:in `call'
rack (2.0.7) lib/rack/sendfile.rb:111:in `call'
actionpack (6.0.0) lib/action_dispatch/middleware/host_authorization.rb:83:in `call'
webpacker (4.0.0) lib/webpacker/dev_server_proxy.rb:29:in `perform_request'
rack-proxy (0.6.5) lib/rack/proxy.rb:57:in `call'
railties (6.0.0) lib/rails/engine.rb:526:in `call'
puma (4.2.1) lib/puma/configuration.rb:228:in `call'
puma (4.2.1) lib/puma/server.rb:667:in `handle_request'
puma (4.2.1) lib/puma/server.rb:470:in `process_client'
puma (4.2.1) lib/puma/server.rb:328:in `block in run'
puma (4.2.1) lib/puma/thread_pool.rb:134:in `block in spawn_thread'

試したこと

①No connection pool with 'primary' found.エラーが表示される前にSQLite(3.7.17)のバージョンが古いとのメッセージが出たため、Gemfileを書き換えました。下記がGemfileの中身です。

git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.6.3'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '6.0.0'
# Use Puma as the app server
gem 'puma', '4.2.1'
# Use SCSS for stylesheets
gem 'sass-rails', '6.0.0'
# Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker
gem 'webpacker', '4.0'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '2.7'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '4.0'
# Use Active Model has_secure_password
# gem 'bcrypt', '3.1.7'

# Use Active Storage variant
# gem 'image_processing', '1.2'

# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', require: false

group :development, :test do
  # Use sqlite3 as the database for Active Record
  gem 'sqlite3', '~> 1.3.6'
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
end

group :development do
  # Access an interactive console on exception pages or by calling 'console' anywhere in the code.
  gem 'web-console', '3.3.0'
  gem 'listen', '3.2.0'
  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
  gem 'spring'
  gem 'spring-watcher-listen', '2.0.0'
end

group :test do
  # Adds support for Capybara system testing and selenium driver
  gem 'capybara', '2.15'
  gem 'selenium-webdriver'
  # Easy installation and use of web drivers to run system tests with browsers
  gem 'webdrivers'
end

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

②Gemfile書き換え後、bundle install実行
③rails sコマンドを実行するとActiveRecordエラーが生じたためサーバーを再起動

補足情報（FW/ツールのバージョンなど）

・macOS Catalina 10.15
・Ruby 2.6.3
・Rails 6.0.0
・bundler 2.0.2
・sqlite3 1.3.13

よろしくお願いいたします。

Answer 1

だいたい同じエラーの記事でSQliteのバージョンを1.3系に書かれているのでおそらくそれで問題ないのかなと思ったんですが
もし、ローカルのデータを消しても大丈夫なのであれば以下のコマンドでデータベースをリセットしてみると変わるかもです。

rails db:drop
rails db:create
rails db:migrate

Comments

[mayok]

ご回答ありがとうございます。
質問掲載後も模索してみましたがやはり解決に至らなかったため、Cloud9で作成したenvironmentを削除し作り直しました。
解決に向けた手段を提示していただき本当にありがとうございました。

[kuraudo]

十分な助言をできずなんと言えば、、
作り直して解決したのであれば良かったです。