CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-6
LiKaZ
LiKaZ

Reputation: 366

Rails app : What is the best way to add default datas to production application

I have a Rails 6 application used in production. When I upgrade my app, I add migrations for new tables and/or columns.

What is the best way if I have to add new default datas ?

I use seed file for initial datas, but is there something like migrations (incremental) to add datas ? I know I can add datas in migrations but I would prefer another place for that.

[EDIT] Do someone know this gem : https://github.com/ilyakatz/data-migrate ? It seems to do what I am looking for.

Upvotes: 0

Views: 243

Answers (2)

LiKaZ
LiKaZ

Reputation: 366

If someone is looking for a simple solution, data_migrate does exactly what I wanted.

https://github.com/ilyakatz/data-migrate

Data migrations are stored in db/data. Data migrations are included in schema migration workflow with simple commands as :

rails db:migrate:with_data

If you can read spanish, this is an interesting documentation on data_migrate : https://la-guia.platan.us/stack/ruby/rails/data_migrate

When it is possible, you should avoid using ActiveRecord models in data migrations. Models are subject to change and if, for example, you have added validations it is possible that your data migrations will not pass.

This is well explained here : https://medium.com/@jeffcoh23/why-you-should-avoid-activerecord-when-using-ruby-on-rails-data-migrate-gem-2651739395d9

A good solution is to call a model created just for data migration :

class AddVisitorRoleToUsers < ActiveRecord::Migration[6.0]
  class MigrationUser < ApplicationRecord
    self.table_name = :users
  end
  
  def up
    MigrationUser.all.each do |user|
      user.update!(role: 'visitor')
      # This will NOT call User model validations
    end
  end

  def down
    raise ActiveRecord::IrreversibleMigration
  end
end

Upvotes: 1

nbennke
nbennke

Reputation: 64

In some projects we use to put data updates into db/data-updates/<UTC TimeStamp>_add_thing.rb. We created an own generator for those, called by rails generate data_update AddThing to create a migration calling / executing the contents from the corresponding update file.

Based on that you can put those default datas into db/default-data with similar logic for your new defaults.

You don't need to call them by mirgrations, you also may run them as rails runner db/default-data/123_xyz.rb in your differnt environments.

But if the new defaults are mandatory for your busines logic you should keep them as close as possible to the inventing migration!

Upvotes: 1

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