perform

# File railties/lib/rails/commands/dbconsole/dbconsole_command.rb, line 173
      def perform
        extract_environment_option_from_argument

        # RAILS_ENV needs to be set before config/application is required.
        ENV["RAILS_ENV"] = options[:environment]

        require_application_and_environment!
        Rails::DBConsole.start(options)
      end