There are several options to specify direction dependent actions in Rails applications
Example 1 - reversible
class AddSlugToUserss < ActiveRecord::Migration
def change
add_column :users, :slug, :string, limit: 64
add_index :users, :slug, unique: true
reversible do |dir|
dir.up do
User.find_each(&:save)
end
end
end
end
Reference: https://apidock.com/rails/ActiveRecord/Migration/reversible
Example 2 - up_only
class AddSlugToUserss < ActiveRecord::Migration
def change
add_column :users, :slug, :string, limit: 64
add_index :users, :slug, unique: true
up_only do |dir|
User.find_each(&:save)
end
end
end
Reference: https://apidock.com/rails/ActiveRecord/Migration/up_only