My Ruby on Rails webapp allows for users to upload an sqlite database in order to export information from that database in a certain format. Locally everything works fine but I can't deploy it to heroku as I am using the sqlite gem. Heroku doesn't allow it even tho I use postgres for the app itself as configured in the database.yml.
Before I move everything to another PaaS I'd like to know are there any other ways to access the information in the sqlite DB without using the sqlite gem?
I'm afraid you can't use SQLite on Heroku (and I discourage you to use it in any production environment).
When deploying to Heroku the database.yml file gets replaced. Reading from the docs:
When an application is deployed, the build phase configures the underlying Rack or Rails application to use the provisioned database if a config directory exists, and a RAILS_ENV or RACK_ENV environment variable is present. Under these conditions, a database.yml file will be created . If a database.yml file already exists, it will be replaced. The database.yml file is created as Ruby code that dynamically creates its output by parsing the DATABASE_URL environment variable.
Source: https://devcenter.heroku.com/articles/ruby-support#build-behavior
If you want to use PostreSQL in Heroku, just put the needed gem in your Gemfile:
gem 'pg', group: :production
