Could not load 'active_record/connection_adapters/sqlite3_adapter' when running Rails

Question

    source 'https://rubygems.org'


# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.2.11'
# Use sqlite3 as the database for Active Record
gem 'sqlite3', '1.3.13' , platform: :ruby
group :development, :production do
  gem 'pg'
end

group :test do
  gem 'sqlite3', '1.3.13'
end
# Use SCSS for stylesheets
# gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
# gem 'uglifier', '>= 1.3.0'

# Use CoffeeScript for .coffee assets and views
# gem 'coffee-rails', '~> 4.1.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use jquery as the JavaScript library
# gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
# gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
# gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
# gem 'sdoc', '~> 0.4.0', group: :doc

# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use Unicorn as the app server
# gem 'unicorn'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug'
end

group :development do
  # Access an IRB console on exception pages or by using <%= console %> in views
  gem 'web-console', '~> 2.0'
end

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

Could not load 'active_record/connection_adapters/sqlite3_adapter'. Make sure that the adapter in config/database.yml is valid. If you use an adapter other than 'mysql', 'mysql2', 'postgresql' or 'sqlite3' add the necessary adapter gem to the Gemfile.

Blockquote

C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/activesupport-4.2.11/lib/active_support/c ore_ext/object/duplicable.rb:111: warning: BigDecimal.new is deprecated; use Big Decimal() method instead.
=> Booting WEBrick
=> Rails 4.2.11 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server [2020-03-23 23:42:51] INFO  WEBrick 1.4.2 [2020-03-23 23:42:51] INFO  ruby 2.6.5 (2019-10-01) [x64-mingw32] [2020-03-23 23:42:51] INFO  WEBrick::HTTPServer#start: pid=3492 port=3000

What does config/database.yml say your adapter is? Did you bundle install? Are you running regular Ruby or JRuby? — tadman
default: &default adapter: sqlite3 pool: 5 timeout: 5000 development: <<: *default database: db/development.sqlite3 # 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: db/test.sqlite3 production: <<: *default database: db/production.sqlite3 — 123s
Check that sqlite3 shows up when doing bundle show. Are you actually intending to use Postgres here, though? — tadman
Don't need to post everything, just asking about sqlite3. Looks like it's having trouble loading that dependency so may need to uninstall and reinstall that gem. — tadman

Masafumi Okura Masafumi Okura · Accepted Answer · 2020-03-24T07:32:31

Here's a documentation for platform usage on Gemfile: https://bundler.io/v2.0/man/gemfile.5.html#PLATFORMS

It says:

ruby

C Ruby (MRI), Rubinius or TruffleRuby, but NOT Windows

Your sqlite3 dependency is for ruby platform, so on Windows it does not get installed.

And you seem on Windows. Therefore sqlite3 does not get installed.

Could not load 'active_record/connection_adapters/sqlite3_adapter' when running Rails

1 Answers