Do I need to use multiple databases in Ruby on Rails application?

Question

I am designing a CRM using Ruby on Rails. How do you think, do I need a separate database for every client company? Or should I use the same database for everyone?

Answer 1

If they are separate companies or competing companies (for say a white label CRM) you'll most definitely want to run separate instances because then you can credibly claim total sandboxing. Otherwise, if you ever inadvertently wrote code that somehow allowed the data from one to display for the other, the game is over. Your customer will run for the hills and tell everyone about their terrible experience with your product.

I would even suggest you run separate instances of your app for each customer. Heroku provides a super simple way to deploy RoR apps so spinning up a new one whenever you add a new customer is a reasonable approach. Of course, if you want a more turnkey solution that allows people to just sign up for an account, you will have to have a single instance that enforces customer data sandboxing in code. Obviously it can be done, but the separation isn't done at the infrastructure level which is ultimately the safest way.

Best regards.

Answer 2

I do it with a single database, like this:

class Company < ActiveRecord::Base
  has_many :records

  def recent_records
   records.desc(:created_at)
  end
end

class Record < ActiveRecord::Base
  belongs_to :company
end 

Then, in the controller, I can write:

@records = @company.recent_records

And pass that down to the views.

Hope this helps.