How can I dynamically change the Active Record database for all models in Ruby on Rails?

Question

In our program, each customer gets their own database. We e-mail them a link that connects them to their database. The link contains a GUID that lets the program know whic

Answer 1

class Database
  def self.development!
    ActiveRecord::Base.establish_connection(:development)
  end

  def self.production!
    ActiveRecord::Base.establish_connection(ENV['PRODUCTION_DATABASE'])
  end

  def self.staging!
    ActiveRecord::Base.establish_connection(ENV['STAGING_DATABASE'])
  end
end

And in .env (with dotenv-rails gem for instance):

PRODUCTION_DATABASE=postgres://...
STAGING_DATABASE=postgres://...

And now you can:

Database.development!
User.count
Database.production!
User.count
Database.staging!
User.count
# etc.