Active Record DatabaseTasks

ActiveRecord::Tasks::DatabaseTasks is a utility class, which encapsulates logic behind common tasks used to manage database and migrations.

The tasks defined here are used with Rails commands provided by Active Record.

In order to use DatabaseTasks, a few config values need to be set. All the needed config values are set by Rails already, so it’s necessary to do it only if you want to change the defaults or when you want to use Active Record outside of Rails (in such case after configuring the database tasks, you can also use the rake tasks defined in Active Record).

The possible config values are:

env: current environment (like Rails.env).
database_configuration: configuration of your databases (as in config/database.yml).
db_dir: your db directory.
fixtures_path: a path to fixtures directory.
migrations_paths: a list of paths to directories with migrations.
seed_loader: an object which will load seeds, it needs to respond to the load_seed method.
root: a path to the root of the application.

Example usage of DatabaseTasks outside Rails could look as such:

include ActiveRecord::Tasks
DatabaseTasks.database_configuration = YAML.load_file('my_database_config.yml')
DatabaseTasks.db_dir = 'db'
# other settings...

DatabaseTasks.create_current('production')

Methods

cache_dump_filename
charset
charset_current
check_protected_environments!
check_schema_file
check_target_version
clear_schema_cache
collation
collation_current
create
create_all
create_current
db_dir
drop
drop_all
drop_current
dump_schema_cache
env
fixtures_path
load_schema_current
load_seed
migrate
migrate_status
migrations_paths
name
prepare_all
purge
purge_all
purge_current
register_task
root
schema_dump_path
schema_up_to_date?
seed_loader
structure_dump
structure_dump_flags
structure_load
structure_load_flags
target_version
truncate_all

Constants

LOCAL_HOSTS

["127.0.0.1", "localhost"]

Attributes

[RW]	database_configuration
[W]	db_dir
[W]	env
[W]	fixtures_path
[W]	migrations_paths
[W]	root
[W]	seed_loader

Class Public methods

structure_dump_flags

Extra flags passed to database CLI tool (mysqldump/pg_dump) when calling db:schema:dump It can be used as a string/array (the typical case) or a hash (when you use multiple adapters) Example:

ActiveRecord::Tasks::DatabaseTasks.structure_dump_flags = {
  mysql2: ['--no-defaults', '--skip-add-drop-table'],
  postgres: '--no-tablespaces'
}

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 50
      mattr_accessor :structure_dump_flags, instance_accessor: false

🔎 See on GitHub

structure_load_flags

Extra flags passed to database CLI tool when calling db:schema:load It can be used as a string/array (the typical case) or a hash (when you use multiple adapters)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 56
      mattr_accessor :structure_load_flags, instance_accessor: false

🔎 See on GitHub

Instance Public methods

cache_dump_filename(db_config_or_name, schema_cache_path: nil)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 441
      def cache_dump_filename(db_config_or_name, schema_cache_path: nil)
        if db_config_or_name.is_a?(DatabaseConfigurations::DatabaseConfig)
          schema_cache_path ||
            db_config_or_name.schema_cache_path ||
            schema_cache_env ||
            db_config_or_name.default_schema_cache_path(ActiveRecord::Tasks::DatabaseTasks.db_dir)
        else
          ActiveRecord.deprecator.warn(<<~MSG.squish)
            Passing a database name to `cache_dump_filename` is deprecated and will be removed in Rails 8.0. Pass a
            `ActiveRecord::DatabaseConfigurations::DatabaseConfig` object instead.
          MSG

          filename = if ActiveRecord::Base.configurations.primary?(db_config_or_name)
            "schema_cache.yml"
          else
            "#{db_config_or_name}_schema_cache.yml"
          end

          schema_cache_path || schema_cache_env || File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, filename)
        end
      end

🔎 See on GitHub

charset(configuration, *arguments)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 305
      def charset(configuration, *arguments)
        db_config = resolve_configuration(configuration)
        database_adapter_for(db_config, *arguments).charset
      end

🔎 See on GitHub

charset_current(env_name = env, db_name = name)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 300
      def charset_current(env_name = env, db_name = name)
        db_config = configs_for(env_name: env_name, name: db_name)
        charset(db_config)
      end

🔎 See on GitHub

check_protected_environments!(environment = env)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 65
      def check_protected_environments!(environment = env)
        return if ENV["DISABLE_DATABASE_ENVIRONMENT_CHECK"]

        configs_for(env_name: environment).each do |db_config|
          check_current_protected_environment!(db_config)
        end
      end

🔎 See on GitHub

check_schema_file(filename)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 471
      def check_schema_file(filename)
        unless File.exist?(filename)
          message = +%{#{filename} doesn't exist yet. Run `bin/rails db:migrate` to create it, then try again.}
          message << %{ If you do not intend to use a database, you should instead alter #{Rails.root}/config/application.rb to limit the frameworks that will be loaded.} if defined?(::Rails.root)
          Kernel.abort message
        end
      end

🔎 See on GitHub

check_target_version()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 290
      def check_target_version
        if target_version && !Migration.valid_version_format?(ENV["VERSION"])
          raise "Invalid format of target version: `VERSION=#{ENV['VERSION']}`"
        end
      end

🔎 See on GitHub

clear_schema_cache(filename)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 497
      def clear_schema_cache(filename)
        FileUtils.rm_f filename, verbose: false
      end

🔎 See on GitHub

collation(configuration, *arguments)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 315
      def collation(configuration, *arguments)
        db_config = resolve_configuration(configuration)
        database_adapter_for(db_config, *arguments).collation
      end

🔎 See on GitHub

collation_current(env_name = env, db_name = name)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 310
      def collation_current(env_name = env, db_name = name)
        db_config = configs_for(env_name: env_name, name: db_name)
        collation(db_config)
      end

🔎 See on GitHub

create(configuration, *arguments)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 115
      def create(configuration, *arguments)
        db_config = resolve_configuration(configuration)
        database_adapter_for(db_config, *arguments).create
        $stdout.puts "Created database '#{db_config.database}'" if verbose?
      rescue DatabaseAlreadyExists
        $stderr.puts "Database '#{db_config.database}' already exists" if verbose?
      rescue Exception => error
        $stderr.puts error
        $stderr.puts "Couldn't create '#{db_config.database}' database. Please check your configuration."
        raise
      end

🔎 See on GitHub

create_all()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 127
      def create_all
        db_config = migration_connection.pool.db_config

        each_local_configuration { |db_config| create(db_config) }

        migration_class.establish_connection(db_config)
      end

🔎 See on GitHub

create_current(environment = env, name = nil)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 170
      def create_current(environment = env, name = nil)
        each_current_configuration(environment, name) { |db_config| create(db_config) }

        migration_class.establish_connection(environment.to_sym)
      end

🔎 See on GitHub

db_dir()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 83
      def db_dir
        @db_dir ||= Rails.application.config.paths["db"].first
      end

🔎 See on GitHub

drop(configuration, *arguments)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 204
      def drop(configuration, *arguments)
        db_config = resolve_configuration(configuration)
        database_adapter_for(db_config, *arguments).drop
        $stdout.puts "Dropped database '#{db_config.database}'" if verbose?
      rescue ActiveRecord::NoDatabaseError
        $stderr.puts "Database '#{db_config.database}' does not exist"
      rescue Exception => error
        $stderr.puts error
        $stderr.puts "Couldn't drop database '#{db_config.database}'"
        raise
      end

🔎 See on GitHub

drop_all()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 216
      def drop_all
        each_local_configuration { |db_config| drop(db_config) }
      end

🔎 See on GitHub

drop_current(environment = env)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 220
      def drop_current(environment = env)
        each_current_configuration(environment) { |db_config| drop(db_config) }
      end

🔎 See on GitHub

dump_schema_cache(conn_or_pool, filename)

Dumps the schema cache in YAML format for the connection into the file

Examples

ActiveRecord::Tasks::DatabaseTasks.dump_schema_cache(ActiveRecord::Base.lease_connection, "tmp/schema_dump.yaml")

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 493
      def dump_schema_cache(conn_or_pool, filename)
        conn_or_pool.schema_cache.dump_to(filename)
      end

🔎 See on GitHub

env()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 103
      def env
        @env ||= Rails.env
      end

🔎 See on GitHub

fixtures_path()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 91
      def fixtures_path
        @fixtures_path ||= if ENV["FIXTURES_PATH"]
          File.join(root, ENV["FIXTURES_PATH"])
        else
          File.join(root, "test", "fixtures")
        end
      end

🔎 See on GitHub

load_schema_current(format = ActiveRecord.schema_format, file = nil, environment = env)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 463
      def load_schema_current(format = ActiveRecord.schema_format, file = nil, environment = env)
        each_current_configuration(environment) do |db_config|
          with_temporary_connection(db_config) do
            load_schema(db_config, format, file)
          end
        end
      end

🔎 See on GitHub

load_seed()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 479
      def load_seed
        if seed_loader
          seed_loader.load_seed
        else
          raise "You tried to load seed data, but no seed loader is specified. Please specify seed " \
                "loader with ActiveRecord::Tasks::DatabaseTasks.seed_loader = your_seed_loader\n" \
                "Seed loader should respond to load_seed method"
        end
      end

🔎 See on GitHub

migrate(version = nil)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 237
      def migrate(version = nil)
        scope = ENV["SCOPE"]
        verbose_was, Migration.verbose = Migration.verbose, verbose?

        check_target_version

        migration_connection_pool.migration_context.migrate(target_version) do |migration|
          if version.blank?
            scope.blank? || scope == migration.scope
          else
            migration.version == version
          end
        end.tap do |migrations_ran|
          Migration.write("No migrations ran. (using #{scope} scope)") if scope.present? && migrations_ran.empty?
        end

        migration_connection_pool.schema_cache.clear!
      ensure
        Migration.verbose = verbose_was
      end

🔎 See on GitHub

migrate_status()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 275
      def migrate_status
        unless migration_connection_pool.schema_migration.table_exists?
          Kernel.abort "Schema migrations table does not exist yet."
        end

        # output
        puts "\ndatabase: #{migration_connection_pool.db_config.database}\n\n"
        puts "#{'Status'.center(8)}  #{'Migration ID'.ljust(14)}  Migration Name"
        puts "-" * 50
        migration_connection_pool.migration_context.migrations_status.each do |status, version, name|
          puts "#{status.center(8)}  #{version.ljust(14)}  #{name}"
        end
        puts
      end

🔎 See on GitHub

migrations_paths()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 87
      def migrations_paths
        @migrations_paths ||= Rails.application.paths["db/migrate"].to_a
      end

🔎 See on GitHub

name()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 107
      def name
        @name ||= "primary"
      end

🔎 See on GitHub

prepare_all()

📝 Source code

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

        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

            migrate
            dump_schema(db_config) if ActiveRecord.dump_schema_after_migration
          end
        end

        load_seed if seed
      end

🔎 See on GitHub

purge(configuration)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 320
      def purge(configuration)
        db_config = resolve_configuration(configuration)
        database_adapter_for(db_config).purge
      end

🔎 See on GitHub

purge_all()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 325
      def purge_all
        each_local_configuration { |db_config| purge(db_config) }
      end

🔎 See on GitHub

purge_current(environment = env)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 329
      def purge_current(environment = env)
        each_current_configuration(environment) { |db_config| purge(db_config) }

        migration_class.establish_connection(environment.to_sym)
      end

🔎 See on GitHub

register_task(pattern, task)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 73
      def register_task(pattern, task)
        @tasks ||= {}
        @tasks[pattern] = task
      end

🔎 See on GitHub

root()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 99
      def root
        @root ||= Rails.root
      end

🔎 See on GitHub

schema_dump_path(db_config, format = ActiveRecord.schema_format)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 428
      def schema_dump_path(db_config, format = ActiveRecord.schema_format)
        return ENV["SCHEMA"] if ENV["SCHEMA"]

        filename = db_config.schema_dump(format)
        return unless filename

        if File.dirname(filename) == ActiveRecord::Tasks::DatabaseTasks.db_dir
          filename
        else
          File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, filename)
        end
      end

🔎 See on GitHub

schema_up_to_date?(configuration, format = ActiveRecord.schema_format, file = nil)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 370
      def schema_up_to_date?(configuration, format = ActiveRecord.schema_format, file = nil)
        db_config = resolve_configuration(configuration)

        file ||= schema_dump_path(db_config)

        return true unless file && File.exist?(file)

        with_temporary_pool(db_config) do |pool|
          internal_metadata = pool.internal_metadata
          return false unless internal_metadata.enabled?
          return false unless internal_metadata.table_exists?

          internal_metadata[:schema_sha1] == schema_sha1(file)
        end
      end

🔎 See on GitHub

seed_loader()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 111
      def seed_loader
        @seed_loader ||= Rails.application
      end

🔎 See on GitHub

structure_dump(configuration, *arguments)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 335
      def structure_dump(configuration, *arguments)
        db_config = resolve_configuration(configuration)
        filename = arguments.delete_at(0)
        flags = structure_dump_flags_for(db_config.adapter)
        database_adapter_for(db_config, *arguments).structure_dump(filename, flags)
      end

🔎 See on GitHub

structure_load(configuration, *arguments)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 342
      def structure_load(configuration, *arguments)
        db_config = resolve_configuration(configuration)
        filename = arguments.delete_at(0)
        flags = structure_load_flags_for(db_config.adapter)
        database_adapter_for(db_config, *arguments).structure_load(filename, flags)
      end

🔎 See on GitHub

target_version()

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 296
      def target_version
        ENV["VERSION"].to_i if ENV["VERSION"] && !ENV["VERSION"].empty?
      end

🔎 See on GitHub

truncate_all(environment = env)

📝 Source code

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 231
      def truncate_all(environment = env)
        configs_for(env_name: environment).each do |db_config|
          truncate_tables(db_config)
        end
      end

🔎 See on GitHub