Gem::LoadError: when trying to deploy on Heroku - Rails 4

Question

I am trying to deploy an app (just a simple app from a Rails tutorial) to heroku but it keeps giving me the same error message. I use the command:

git push heroku master

It starts well, and then suddenly appears this error:

-----> Preparing app for Rails asset pipeline
       Running: rake assets:precompile
       rake aborted!
       Gem::LoadError: Specified 'sqlite3' for database adapter, but the gem is not loaded. Add `gem 'sqlite3'` to your Gemfile.

I did bundle install already, everything went smooth there.

Here is my Gemfile:

# Use sqlite3 as the database for Active Record
gem 'sqlite3'

Maybe something I am missing something on databse.yml file?

#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000

# 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:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

production:
  adapter: sqlite3
  database: db/production.sqlite3
  pool: 5
  timeout: 5000

By the way, I don't know if it helps, but I am using Rails 4.0.4, Ruby 2.1.1 and the version of SQLite which comes already installed on Mac, which is 3.7.13

Answer 1

Kirti is right in saying that Heroku does not support sqlite as adapter,

do the following

in the Gemfile:

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

group :development, :test do
  gem 'sqlite3'
end

in database.yml

production:
  adapter: postgresql
  database: name_of_your_db
  pool: 5
  timeout: 5000

Answer 2

SQLite is not intended as a production grade database. Instead Heroku provides production grade PostgreSQL databases as a service.

Read the details SQLite on Heroku