rails db:rollbackを禁止したいときはActiveRecord::IrreversibleMigrationを使う
class SomethingMigration < ActiveRecord::Migration[5.0] def up # Add migration code end def down raise ActiveRecord::IrreversibleMigration end end
class SomethingMigration < ActiveRecord::Migration[5.0] def up # Add migration code end def down raise ActiveRecord::IrreversibleMigration end end