几天前我开始使用“rails tutorial”开始在rails上学习ruby，我已经遇到了下面的错误。
Application error
An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details.
尝试部署应用时出现此错误：
ec2-user:~/environment/hello_app (master) $ heroku create
ec2-user:~/environment/hello_app (master) $ git push heroku master
Counting objects: 1, done.
Writing objects: 100% (1/1), 211 bytes | 211.00 KiB/s, done.
Total 1 (delta 0), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Ruby app detected
remote: -----> Compiling Ruby/Rails
remote: -----> Using Ruby version: ruby-2.3.4
remote: -----> Installing dependencies using bundler 1.15.2
remote: Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin -j4 --deployment
remote: Warning: the running version of Bundler (1.15.2) is older than the version that created the lockfile (1.16.1). We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
remote: Fetching gem metadata from https://rubygems.org/.........
remote: Fetching version metadata from https://rubygems.org/..
remote: Fetching dependency metadata from https://rubygems.org/.
remote: Using rake 12.3.0
remote: Using concurrent-ruby 1.0.5
remote: Using minitest 5.11.3
remote: Using thread_safe 0.3.6
remote: Using builder 3.2.3
remote: Using erubi 1.7.1
remote: Using mini_portile2 2.3.0
remote: Using crass 1.0.3
remote: Using rack 2.0.4
remote: Using nio4r 2.2.0
remote: Using websocket-extensions 0.1.3
remote: Using mini_mime 1.0.0
remote: Using arel 8.0.0
remote: Using bundler 1.15.2
remote: Using coffee-script-source 1.12.2
remote: Using execjs 2.7.0
remote: Using method_source 0.9.0
remote: Using thor 0.20.0
remote: Using ffi 1.9.23
remote: Using multi_json 1.13.1
remote: Using puma 3.9.1
remote: Using rb-fsevent 0.10.3
remote: Using tilt 2.0.8
remote: Using turbolinks-source 5.1.0
remote: Using tzinfo 1.2.5
remote: Using nokogiri 1.8.2
remote: Using i18n 0.9.5
remote: Using rack-test 0.8.3
remote: Using sprockets 3.7.1
remote: Using websocket-driver 0.6.5
remote: Using mail 2.7.0
remote: Using coffee-script 2.4.1
remote: Using uglifier 3.2.0
remote: Using rb-inotify 0.9.10
remote: Using turbolinks 5.0.1
remote: Using loofah 2.2.0
remote: Using activesupport 5.1.4
remote: Using sass-listen 4.0.0
remote: Using rails-html-sanitizer 1.0.3
remote: Using sass 3.5.5
remote: Using rails-dom-testing 2.0.3
remote: Using globalid 0.4.1
remote: Using activemodel 5.1.4
remote: Using jbuilder 2.6.4
remote: Using actionview 5.1.4
remote: Using activejob 5.1.4
remote: Using activerecord 5.1.4
remote: Using actionpack 5.1.4
remote: Using actioncable 5.1.4
remote: Using actionmailer 5.1.4
remote: Using railties 5.1.4
remote: Using sprockets-rails 3.2.1
remote: Using coffee-rails 4.2.2
remote: Using jquery-rails 4.3.1
remote: Using rails 5.1.4
remote: Using sass-rails 5.0.6
remote: Bundle complete! 15 Gemfile dependencies, 56 gems now installed.
remote: Gems in the groups development and test were not installed.
remote: Bundled gems are installed into ./vendor/bundle.
remote: Bundle completed (3.14s)
remote: Cleaning up the bundler cache.
remote: Warning: the running version of Bundler (1.15.2) is older than the version that created the lockfile (1.16.1). We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
remote: The latest bundler is 1.16.1, but you are currently running 1.15.2.
remote: To update, run `gem install bundler`
remote: -----> Installing node-v6.11.1-linux-x64
remote: -----> Detecting rake tasks
remote: -----> Preparing app for Rails asset pipeline
remote: Running: rake assets:precompile
remote: Yarn executable was not detected in the system.
remote: Download Yarn at https://yarnpkg.com/en/docs/install
remote: Asset precompilation completed (1.65s)
remote: Cleaning assets
remote: Running: rake assets:clean
remote:
remote: ###### WARNING:
remote: You have not declared a Ruby version in your Gemfile.
remote: To set your Ruby version add this line to your Gemfile:
remote: ruby '2.3.4'
remote: # See https://devcenter.heroku.com/articles/ruby-versions for more information.
remote:
remote: -----> Discovering process types
remote: Procfile declares types -> web
remote: Default types for buildpack -> console, rake, worker
remote:
remote: -----> Compressing...
remote: Done: 35.8M
remote: -----> Launching...
remote: Released v9
remote: https://obscure-lake-54868.herokuapp.com/ deployed to Heroku
remote:
remote: Verifying deploy... done.
To https://git.heroku.com/obscure-lake-54868.git
37e8a0c..97c59d3 master -> master
我将行ruby '2.3.4'添加到Gemfile，但此警告仍然不会消失。正如这个错误所说，我跑heroku logs，但我不知道如何解决这个问题。以下是heroku logs的结果。对不起，超长。
ec2-user:~/environment/hello_app (master) $ heroku logs
2018-03-16T05:35:32.900603+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/command.rb:44:in `invoke'
2018-03-16T05:35:32.900608+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/commands.rb:16:in `<top (required)>'
2018-03-16T05:35:32.900610+00:00 app[web.1]: from bin/rails:9:in `require'
2018-03-16T05:35:32.900612+00:00 app[web.1]: from bin/rails:9:in `<main>'
2018-03-16T05:35:32.912746+00:00 app[web.1]: => Booting Puma
2018-03-16T05:35:32.912753+00:00 app[web.1]: => Rails 5.1.4 application starting in production
2018-03-16T05:35:32.912755+00:00 app[web.1]: => Run `rails server -h` for more startup options
2018-03-16T05:35:32.912756+00:00 app[web.1]: Exiting
2018-03-16T05:35:33.004749+00:00 heroku[web.1]: State changed from starting to crashed
2018-03-16T05:35:33.006915+00:00 heroku[web.1]: State changed from crashed to starting
2018-03-16T05:35:32.972692+00:00 heroku[web.1]: Process exited with status 1
2018-03-16T05:35:36.687462+00:00 heroku[web.1]: Starting process with command `bin/rails server -p 4593 -e production`
2018-03-16T05:35:41.293329+00:00 heroku[web.1]: State changed from starting to crashed
2018-03-16T05:35:41.279319+00:00 heroku[web.1]: Process exited with status 1
2018-03-16T05:35:41.177337+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_adapters/connection_specification.rb:185:in `spec'
2018-03-16T05:35:41.177313+00:00 app[web.1]: /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': Specified 'sqlite3' for database adapter, but the gem is not loaded. Add `gem 'sqlite3'` to your Gemfile (and ensure its version is at the minimum required by ActiveRecord). (Gem::LoadError)
2018-03-16T05:35:41.177352+00:00 app[web.1]: from /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'
2018-03-16T05:35:41.177354+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/connection_handling.rb:58:in `establish_connection'
2018-03-16T05:35:41.177360+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/railtie.rb:124:in `block (2 levels) in <class:Railtie>'
2018-03-16T05:35:41.177362+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/lazy_load_hooks.rb:69:in `instance_eval'
2018-03-16T05:35:41.177364+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/lazy_load_hooks.rb:69:in `block in execute_hook'
2018-03-16T05:35:41.177365+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/lazy_load_hooks.rb:60:in `with_execution_control'
2018-03-16T05:35:41.177366+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/lazy_load_hooks.rb:65:in `execute_hook'
2018-03-16T05:35:41.177368+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/lazy_load_hooks.rb:50:in `block in run_load_hooks'
2018-03-16T05:35:41.177370+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/lazy_load_hooks.rb:49:in `each'
2018-03-16T05:35:41.177371+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/lazy_load_hooks.rb:49:in `run_load_hooks'
2018-03-16T05:35:41.177373+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/base.rb:326:in `<module:ActiveRecord>'
2018-03-16T05:35:41.177374+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.1.4/lib/active_record/base.rb:25:in `<top (required)>'
2018-03-16T05:35:41.177376+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
2018-03-16T05:35:41.177378+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
2018-03-16T05:35:41.177379+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
2018-03-16T05:35:41.177381+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
2018-03-16T05:35:41.177382+00:00 app[web.1]: from /app/app/models/application_record.rb:1:in `<top (required)>'
2018-03-16T05:35:41.177387+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
2018-03-16T05:35:41.177388+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `block in require'
2018-03-16T05:35:41.177390+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:258:in `load_dependency'
2018-03-16T05:35:41.177391+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:292:in `require'
2018-03-16T05:35:41.177393+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:379:in `block in require_or_load'
2018-03-16T05:35:41.177394+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:36:in `block in load_interlock'
2018-03-16T05:35:41.177396+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies/interlock.rb:12:in `block in loading'
2018-03-16T05:35:41.177398+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/concurrency/share_lock.rb:149:in `exclusive'
2018-03-16T05:35:41.177399+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies/interlock.rb:11:in `loading'
2018-03-16T05:35:41.177404+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:36:in `load_interlock'
2018-03-16T05:35:41.177405+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:357:in `require_or_load'
2018-03-16T05:35:41.177407+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:335:in `depend_on'
2018-03-16T05:35:41.177408+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.4/lib/active_support/dependencies.rb:251:in `require_dependency'
2018-03-16T05:35:41.177410+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/engine.rb:476:in `block (2 levels) in eager_load!'
2018-03-16T05:35:41.177412+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/engine.rb:475:in `each'
2018-03-16T05:35:41.177416+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/engine.rb:475:in `block in eager_load!'
2018-03-16T05:35:41.177418+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/engine.rb:473:in `each'
2018-03-16T05:35:41.177420+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/engine.rb:473:in `eager_load!'
2018-03-16T05:35:41.177421+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/engine.rb:354:in `eager_load!'
2018-03-16T05:35:41.177423+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/application/finisher.rb:67:in `each'
2018-03-16T05:35:41.177428+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/application/finisher.rb:67:in `block in <module:Finisher>'
2018-03-16T05:35:41.177429+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/initializable.rb:30:in `instance_exec'
2018-03-16T05:35:41.177431+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/initializable.rb:30:in `run'
2018-03-16T05:35:41.177432+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/initializable.rb:59:in `block in run_initializers'
2018-03-16T05:35:41.177436+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:228:in `block in tsort_each'
2018-03-16T05:35:41.177474+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
2018-03-16T05:35:41.177526+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:349:in `block in each_strongly_connected_component'
2018-03-16T05:35:41.177502+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:431:in `each_strongly_connected_component_from'
2018-03-16T05:35:41.177550+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `each'
2018-03-16T05:35:41.177575+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `call'
2018-03-16T05:35:41.177599+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `each_strongly_connected_component'
2018-03-16T05:35:41.177623+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:226:in `tsort_each'
2018-03-16T05:35:41.177646+00:00 app[web.1]: from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:205:in `tsort_each'
2018-03-16T05:35:41.177673+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/initializable.rb:58:in `run_initializers'
2018-03-16T05:35:41.177720+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/application.rb:353:in `initialize!'
2018-03-16T05:35:41.177748+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
2018-03-16T05:35:41.177773+00:00 app[web.1]: from config.ru:3:in `require_relative'
2018-03-16T05:35:41.177798+00:00 app[web.1]: from config.ru:3:in `block in <main>'
2018-03-16T05:35:41.177822+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/builder.rb:55:in `instance_eval'
2018-03-16T05:35:41.177846+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/builder.rb:55:in `initialize'
2018-03-16T05:35:41.177871+00:00 app[web.1]: from config.ru:in `new'
2018-03-16T05:35:41.177896+00:00 app[web.1]: from config.ru:in `<main>'
2018-03-16T05:35:41.177920+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/builder.rb:49:in `eval'
2018-03-16T05:35:41.177944+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/builder.rb:49:in `new_from_string'
2018-03-16T05:35:41.177968+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/builder.rb:40:in `parse_file'
2018-03-16T05:35:41.177992+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/server.rb:319:in `build_app_and_options_from_config'
2018-03-16T05:35:41.178019+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/server.rb:219:in `app'
2018-03-16T05:35:41.178045+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/server_command.rb:24:in `app'
2018-03-16T05:35:41.178071+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/server.rb:354:in `wrapped_app'
2018-03-16T05:35:41.178096+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.4/lib/rack/server.rb:283:in `start'
2018-03-16T05:35:41.178121+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/server_command.rb:44:in `start'
2018-03-16T05:35:41.178152+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/server_command.rb:135:in `block in perform'
2018-03-16T05:35:41.178177+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/server_command.rb:130:in `tap'
2018-03-16T05:35:41.178199+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/server_command.rb:130:in `perform'
2018-03-16T05:35:41.178247+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in `invoke_command'
2018-03-16T05:35:41.178223+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/thor-0.20.0/lib/thor/command.rb:27:in `run'
2018-03-16T05:35:41.178272+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/thor-0.20.0/lib/thor.rb:387:in `dispatch'
2018-03-16T05:35:41.178295+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/command/base.rb:63:in `perform'
2018-03-16T05:35:41.178319+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/command.rb:44:in `invoke'
2018-03-16T05:35:41.178341+00:00 app[web.1]: from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.4/lib/rails/commands.rb:16:in `<top (required)>'
2018-03-16T05:35:41.178363+00:00 app[web.1]: from bin/rails:9:in `require'
2018-03-16T05:35:41.178388+00:00 app[web.1]: from bin/rails:9:in `<main>'
2018-03-16T05:35:41.196457+00:00 app[web.1]: => Booting Puma
2018-03-16T05:35:41.196462+00:00 app[web.1]: => Rails 5.1.4 application starting in production
2018-03-16T05:35:41.196464+00:00 app[web.1]: => Run `rails server -h` for more startup options
2018-03-16T05:35:41.196466+00:00 app[web.1]: Exiting
2018-03-16T05:35:42.194333+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=obscure-lake-54868.herokuapp.com request_id=5db8303d-ff52-4273-a347-a73b46ef1d72 fwd="115.165.98.19" dyno= connect= service= status=503 bytes= protocol=https
2018-03-16T05:35:42.900389+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=obscure-lake-54868.herokuapp.com request_id=37e231a2-72ce-45da-95a3-0f0301c50abd fwd="115.165.98.19" dyno= connect= service= status=503 bytes= protocol=https
访问其他网站后，我尝试$ heroku ps:restart web.1，但错误并未消失。任何人都可以帮我吗？
我不擅长英语，请原谅我一些语法错误。
*下面是我的Gemfile
source 'https://rubygems.org'
ruby "2.3.4"
gem 'rails', '5.1.4'
gem 'puma', '3.9.1'
gem 'sass-rails', '5.0.6'
gem 'uglifier', '3.2.0'
gem 'coffee-rails', '4.2.2'
gem 'jquery-rails', '4.3.1'
gem 'turbolinks', '5.0.1'
gem 'jbuilder', '2.6.4'
group :development, :test do
gem 'sqlite3', '1.3.13'
gem 'byebug', '9.0.6', platform: :mri
end
group :development do
gem 'web-console', '3.5.1'
gem 'listen', '3.1.5'
gem 'spring', '2.0.2'
gem 'spring-watcher-listen', '2.0.1'
end
group :production do
gem 'pg', '~> 0.20.0'
end
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
答案 0 :(得分：1)
因为您必须在全局范围内sqlite3 Gemfile，所以您需要为开发指定数据库gem＆amp;单独制作，就像你的Gemfile
小组制作
group :production do
gem 'pg', '~> 0.11'
#Or
#gem 'pg', '~> 0.20.0'
end
注意： 在>之前的波形符号，这不是短划线
小组测试＆amp;发展
group :test, :development do
gem 'sqlite3'
end
然后bundle install --without production（更新Gemfile.lock文件）执行git add / commit循环，然后重新部署到Heroku。
然后heroku run rake db:setup或heroku run rake db:create和heroku run rake db:migrate
<强>更新
生产区块上的 database.yml
示例结构
production:
<<: *default
database: project_name_production
username: project_name
password: <%= ENV['PROJECT_NAME_DATABASE_PASSWORD'] %>
在使用Heroku
创建rails项目时，默认情况下会创建此结构