puyopuyotetr.is/db/migrate/20170109120109_create_web_settings.rb

# frozen_string_literal: true

class CreateWebSettings < ActiveRecord::Migration[5.0]
  def change
    create_table :web_settings do |t|
      t.integer :user_id
      t.json :data

      t.timestamps
    end

    add_index :web_settings, :user_id, unique: true
  end
end