reconstruct_from_schema

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 398
      def reconstruct_from_schema(db_config, format = ActiveRecord.schema_format, file = nil) # :nodoc:
        file ||= schema_dump_path(db_config, format)

        check_schema_file(file)

        ActiveRecord::Base.establish_connection(db_config)

        if schema_up_to_date?(db_config, format, file)
          truncate_tables(db_config)
        else
          purge(db_config)
          load_schema(db_config, format, file)
        end
      rescue ActiveRecord::NoDatabaseError
        create(db_config)
        load_schema(db_config, format, file)
      end