How to use UUID for Rails API

In application.rb, add the following line:

config.generators do |g|
   g.orm :active_record, primary_key_type: :uuid
end

Create a new migration from the command line:

rails g migration enable_uuid

You should get a file that looks like this:

class EnableUuid < ActiveRecord::Migration[6.0]
end

Then add this method inside that migration to enable uuid:

class EnableUuid < ActiveRecord::Migration[6.0]
   def change
      enable_extension 'uuid-ossp'
      enable_extension 'pgcrypto'
   end
end

Finally, in your regular migrations, you can set the id type to uuid:

class CreateUsers < ActiveRecord::Migration[6.0]
   def change
      create_table :users, id: :uuid do |t|
         t.string :username
         t.timestamps
      end
   end
end

When you run rails db:migrate, your schema for theUser model should then look like this:

create_table "devices", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|
   t.string "username"
   t.datetime "created_at", precision: 6, null: false
   t.datetime "updated_at", precision: 6, null: false
end