Question

I am currently making my way through the Ruby on Rails tutorial over at http://ruby.railstutorial.org/ and I am trying to migrate the demo_app database to heroku.

heroku rake db:migrate
    rake aborted!
    unable to open database file

I have read on other stackoverflow posts that some people fixed this by entering

group :production, :staging do
  gem "pg"
end

group :development, :test do  
  gem "sqlite3-ruby", "~> 1.3.0", :require => "sqlite3"
end

in the gemfile. I also entered it into my gemfile and then deleted my old gemfile.lock and redid my bundle install AND rake db:migrate command. I am still receiving the same error.

I am obviously brand new to ruby, rails and heroku but I understand that the problem seems to be that I am using sqlite locally and postgresql in production (on heroku). Do I now have to install this postgresql onto my machine and then RE-migrate the DB? I am afraid I will not be able to get much more out of the tutorials (or ruby on rails itself) if I cannot use heroku.

Answer 1

Kill it!

I was having the same problem and found no solutions. I think something we are doing in those tutorials is leading us to mangle the database.yml file that heroku generates.

I ended up destroying my heroku app

heroku destroy

and then creating a new one, pushing a fresh copy, and running

heroku create
git push heroku master
heroku rakedb:migrate

This time everything worked fine! Just make sure you have the pg gem in your gemfile for production

group :production do
  gem "pg"
end

and add config/database.yml to your .gitignore file too for good measure.