dump_schema

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 443
      def dump_schema(db_config, format = db_config.schema_format) # :nodoc:
        return unless db_config.schema_dump

        require "active_record/schema_dumper"
        filename = schema_dump_path(db_config, format)
        return unless filename

        with_temporary_pool(db_config) do |pool|
          FileUtils.mkdir_p(db_dir)
          case format.to_sym
          when :ruby
            File.open(filename, "w:utf-8") do |file|
              ActiveRecord::SchemaDumper.dump(pool, file)
            end
          when :sql
            structure_dump(db_config, filename)
            if pool.schema_migration.table_exists?
              File.open(filename, "a") do |f|
                pool.with_connection do |connection|
                  f.puts connection.dump_schema_versions
                end
                f.print "\n"
              end
            end
          end
        end
      end