Heroku在我的Rails应用程序Gemfile中无法识别“ pg”宝石

Question

I'm still a relative newbie to Ruby on Rails, and I'm a complete newbie with Heroku.

I've set up my Rails app to use postgres instead of sqlite3, both in development and in production, and I've put "gem 'pg'" in my Gemfile. And locally, my app is working just fine.

Making it work on Heroku is a different story. After I've pushed my app to Heroku, when I type in "heroku run rake db:migrate", it tells me, "rake aborted! Specified 'postgresql' for database adapter, but the gem is not loaded. Add gem 'pg' to your Gemfile."

Yes, gem 'pg' is in my Gemfile, but I'm still getting this error.

What gives?

Here's what my Gemfile looks like right now:

source 'https://rubygems.org'
ruby '2.0.0'
gem 'rails',        '4.0.1'
gem 'pg'

group :assets do
end

gem 'bcrypt-ruby', '~> 3.1.2'
gem 'haml'
gem 'devise', '3.0.0.rc'
gem 'protected_attributes'
gem 'sass-rails', '4.0.1'
gem 'uglifier', '2.1.1'
gem 'coffee-rails', '4.0.1'
gem 'jquery-rails', '3.0.4'
gem 'turbolinks', '1.1.1'
gem 'jbuilder', '1.0.2'
gem 'knockout-rails'

# To use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.0.0'

# To use Jbuilder templates for JSON
# gem 'jbuilder'

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

# Deploy with Capistrano
# gem 'capistrano'

# To use debugger
# gem 'debugger'

group :doc do
  gem 'sdoc', '0.3.20', require: false
end

group :production do
  gem 'unicorn'
  gem 'rails_12factor', '0.0.2'
end

Here's what my database.yml is like:

development:
  adapter: postgresql
  encoding: unicode
  database: financemeter
  pool: 5
  password:

test:
  adapter: postgresql
  encoding: unicode
  database: financemeter
  pool: 5
  timeout: 5000

production:
  adapter: postgresql
  database: dbe67fgdnnqg88
  pool: 5
  timeout: 5000
  user: njatxlpjjrzfoe
  password: HULxOtPALAk4FnzZe-_737TvPc

And here are the full error logs when I try to migrate on heroku. (Again, locally I'm fine. I'm working locally on a MacBook if that matters.)

/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.1/lib/active_record/connection_adapters/connection_specification.rb:58:in `rescue in resolve_hash_connection'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.1/lib/active_record/connection_adapters/connection_specification.rb:55:in `resolve_hash_connection'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.1/lib/active_record/connection_adapters/connection_specification.rb:46:in `resolve_string_connection'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.1/lib/active_record/connection_adapters/connection_specification.rb:32:in `spec'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.1/lib/active_record/connection_handling.rb:39:in `establish_connection'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.1/lib/active_record/railtie.rb:176:in `block (2 levels) in <class:Railtie>'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/lazy_load_hooks.rb:27:in `each'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
/app/vendor/bundle/ruby/2.0.0/gems/activerecord-4.0.1/lib/active_record/railtie.rb:174:in `block in <class:Railtie>'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/initializable.rb:30:in `instance_exec'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/initializable.rb:30:in `run'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/initializable.rb:55:in `block in run_initializers'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/initializable.rb:54:in `run_initializers'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/application.rb:215:in `initialize!'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/railtie/configurable.rb:30:in `method_missing'
/app/config/environment.rb:5:in `<top (required)>'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `block in require'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:214:in `load_dependency'
/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.1/lib/active_support/dependencies.rb:229:in `require'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/application.rb:189:in `require_environment!'
/app/vendor/bundle/ruby/2.0.0/gems/railties-4.0.1/lib/rails/application.rb:250:in `block in run_tasks_blocks'

Answer 1

Do you have postgresql installed on your machine?
If not, use homebrew to install pg.
Once installed, make sure you initialize the pg datastore.

also, depending how your pg is installed, you might need to specify the username and host in your database.yml file

  username: someuser_on_pg
  host: localhost

Hope that helps