ruby-on-rails - 将 Sqlite3 更改为 Postgresql Rails

Question

我想在 Heroku 上托管我的 Ruby on Rails 应用程序。但首先我需要将我的数据库从 Sqlite3 更改为 Heroku。所以我遵循这些说明:

https://devcenter.heroku.com/articles/sqlite3

这是我的 Gemfile 的样子

    source 'https://rubygems.org'

git_source(:github) do |repo_name|
  repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
  "https://github.com/#{repo_name}.git"
end

gem 'swagger-docs'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.1.4'
# Use sqlite3 as the database for Active Record
gem 'pg'
# Use Puma as the app server
gem 'puma', '~> 3.7'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# 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', '~> 2.5'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 3.0'
# Use ActiveModel has_secure_password
gem 'bcrypt', '~> 3.1.7'

# 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', platforms: [:mri, :mingw, :x64_mingw]
  # Adds support for Capybara system testing and selenium driver
  gem 'capybara', '~> 2.13'
  gem 'selenium-webdriver'
  gem 'rspec-rails'
end

group :development do
  # Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
  gem 'web-console', '>= 3.3.0'
  gem 'listen', '>= 3.0.5', '< 3.2'
  # 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'
  gem 'rails-erd'
end

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

下面是当我尝试运行 rake db:create、rake db:migrate 时发生的情况:(当然是在运行 bundle install 之后)

patryk@LenovoY510P ~/Railsapp/test/Movies_app $ rake db:createSpecified 'postgresql' for database adapter, but the gem is not loaded. Add `gem 'pg'` to your Gemfile (and ensure its version is at the minimum required by ActiveRecord).
Couldn't create database for {"adapter"=>"postgresql", "pool"=>5, "timeout"=>5000, "database"=>"my_database_development"}
rake aborted!
Gem::LoadError: Specified 'postgresql' for database adapter, but the gem is not loaded. Add `gem 'pg'` to your Gemfile (and ensure its version is at the minimum required by ActiveRecord).
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_adapters/connection_specification.rb:188:in `rescue in spec'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_adapters/connection_specification.rb:185:in `spec'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:880:in `establish_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_handling.rb:58:in `establish_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:10:in `establish_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:94:in `establish_master_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:18:in `create'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:117:in `create'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:137:in `block in create_current'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:304:in `block in each_current_configuration'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:303:in `each'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:303:in `each_current_configuration'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:136:in `create_current'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/railties/databases.rake:27:in `block (2 levels) in <top (required)>'
/var/lib/gems/2.3.0/gems/rake-12.3.0/exe/rake:27:in `<top (required)>'

Caused by:
Gem::LoadError: can't activate pg (~> 0.18), already activated pg-0.17.1. Make sure all dependencies are added to Gemfile.
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:2:in `<top (required)>'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_adapters/connection_specification.rb:186:in `spec'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:880:in `establish_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_handling.rb:58:in `establish_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:10:in `establish_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:94:in `establish_master_connection'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:18:in `create'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:117:in `create'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:137:in `block in create_current'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:304:in `block in each_current_configuration'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:303:in `each'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:303:in `each_current_configuration'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:136:in `create_current'
/home/patryk/Railsapp/test/Movies_app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/railties/databases.rake:27:in `block (2 levels) in <top (required)>'
/var/lib/gems/2.3.0/gems/rake-12.3.0/exe/rake:27:in `<top (required)>'
Tasks: TOP => db:create
(See full trace by running task with --trace)

如您所见，我已经将 gem 'sqlite3' 更改为 gem 'pg' 与 database.yml 文件相同。我应该怎么做才能解决这个问题？

Answer 1

Only pg database is used on heroku.

所以用代码修改你的 Gemfile:

gem 'pg'

使用上面的代码，你可以工作 pg db is used on heroku/

运行 bundle install 然后将 Gemfile 和 Gemfile.lock 推送到 heroku。

然后运行 ​​heroku run rake db:migrate 运行所有迁移并创建表。

如果仍然出错，请尝试:

gem 'pg', '~> 0.20', group: :production