class UpdateSettings < ActiveRecord::Migration[6.0]
  def self.up
    remove_column :settings, :thing_id rescue nil
    remove_column :settings, :thing_type rescue nil

    remove_index :settings, name: 'index_settings_on_thing_type_and_thing_id_and_var' rescue nil
    add_index :settings, %i(var), unique: true rescue nil
  end

  def self.down
  end
end