prepare_all

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 176
      def prepare_all
        seed = false
        dump_db_configs = []

        each_current_configuration(env) do |db_config|
          with_temporary_pool(db_config) do
            begin
              database_initialized = migration_connection_pool.schema_migration.table_exists?
            rescue ActiveRecord::NoDatabaseError
              create(db_config)
              retry
            end

            unless database_initialized
              if File.exist?(schema_dump_path(db_config))
                load_schema(db_config, ActiveRecord.schema_format, nil)
              end

              seed = true
            end
          end
        end

        each_current_environment(env) do |environment|
          db_configs_with_versions(environment).sort.each do |version, db_configs|
            dump_db_configs |= db_configs

            db_configs.each do |db_config|
              with_temporary_pool(db_config) do
                migrate(version)
              end
            end
          end
        end

        # Dump schema for databases that were migrated.
        if ActiveRecord.dump_schema_after_migration
          dump_db_configs.each do |db_config|
            with_temporary_pool(db_config) do
              dump_schema(db_config)
            end
          end
        end

        load_seed if seed
      end