module ActiveRecord::Tasks::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:

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')

Constants

LOCAL_HOSTS

Attributes

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

Public Class Methods

structure_dump_flags() click to toggle source

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'
}
# File lib/active_record/tasks/database_tasks.rb, line 48
mattr_accessor :structure_dump_flags, instance_accessor: false
structure_load_flags() click to toggle source

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)

# File lib/active_record/tasks/database_tasks.rb, line 54
mattr_accessor :structure_load_flags, instance_accessor: false

Public Instance Methods

cache_dump_filename(db_config_name, schema_cache_path: nil) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 470
def cache_dump_filename(db_config_name, schema_cache_path: nil)
  filename = if ActiveRecord::Base.configurations.primary?(db_config_name)
    "schema_cache.yml"
  else
    "#{db_config_name}_schema_cache.yml"
  end

  schema_cache_path || ENV["SCHEMA_CACHE"] || File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, filename)
end
charset(configuration, *arguments) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 324
def charset(configuration, *arguments)
  db_config = resolve_configuration(configuration)
  database_adapter_for(db_config, *arguments).charset
end
charset_current(env_name = env, db_name = name) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 319
def charset_current(env_name = env, db_name = name)
  db_config = configs_for(env_name: env_name, name: db_name)
  charset(db_config)
end
check_protected_environments!() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 63
def check_protected_environments!
  unless ENV["DISABLE_DATABASE_ENVIRONMENT_CHECK"]
    current = ActiveRecord::Base.connection.migration_context.current_environment
    stored  = ActiveRecord::Base.connection.migration_context.last_stored_environment

    if ActiveRecord::Base.connection.migration_context.protected_environment?
      raise ActiveRecord::ProtectedEnvironmentError.new(stored)
    end

    if stored && stored != current
      raise ActiveRecord::EnvironmentMismatchError.new(current: current, stored: stored)
    end
  end
rescue ActiveRecord::NoDatabaseError
end
check_schema_file(filename) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 487
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
check_target_version() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 309
def check_target_version
  if target_version && !(Migration::MigrationFilenameRegexp.match?(ENV["VERSION"]) || /\A\d+\z/.match?(ENV["VERSION"]))
    raise "Invalid format of target version: `VERSION=#{ENV['VERSION']}`"
  end
end
clear_schema_cache(filename) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 513
def clear_schema_cache(filename)
  FileUtils.rm_f filename, verbose: false
end
collation(configuration, *arguments) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 334
def collation(configuration, *arguments)
  db_config = resolve_configuration(configuration)
  database_adapter_for(db_config, *arguments).collation
end
collation_current(env_name = env, db_name = name) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 329
def collation_current(env_name = env, db_name = name)
  db_config = configs_for(env_name: env_name, name: db_name)
  collation(db_config)
end
create(configuration, *arguments) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 120
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
create_all() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 132
def create_all
  old_pool = ActiveRecord::Base.connection_handler.retrieve_connection_pool(ActiveRecord::Base.connection_specification_name)
  each_local_configuration { |db_config| create(db_config) }
  if old_pool
    ActiveRecord::Base.connection_handler.establish_connection(old_pool.db_config)
  end
end
create_current(environment = env, name = nil) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 183
def create_current(environment = env, name = nil)
  each_current_configuration(environment, name) { |db_config| create(db_config) }
  ActiveRecord::Base.establish_connection(environment.to_sym)
end
db_dir() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 88
def db_dir
  @db_dir ||= Rails.application.config.paths["db"].first
end
drop(configuration, *arguments) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 222
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
drop_all() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 234
def drop_all
  each_local_configuration { |db_config| drop(db_config) }
end
drop_current(environment = env) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 238
def drop_current(environment = env)
  each_current_configuration(environment) { |db_config| drop(db_config) }
end
dump_schema_cache(conn, filename) click to toggle source

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

Examples:

ActiveRecord::Tasks::DatabaseTasks.dump_schema_cache(ActiveRecord::Base.connection, "tmp/schema_dump.yaml")
# File lib/active_record/tasks/database_tasks.rb, line 509
def dump_schema_cache(conn, filename)
  conn.schema_cache.dump_to(filename)
end
env() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 108
def env
  @env ||= Rails.env
end
fixtures_path() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 96
def fixtures_path
  @fixtures_path ||= if ENV["FIXTURES_PATH"]
    File.join(root, ENV["FIXTURES_PATH"])
  else
    File.join(root, "test", "fixtures")
  end
end
for_each(databases) { |name| ... } click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 154
def for_each(databases)
  return {} unless defined?(Rails)

  database_configs = ActiveRecord::DatabaseConfigurations.new(databases).configs_for(env_name: Rails.env)

  # if this is a single database application we don't want tasks for each primary database
  return if database_configs.count == 1

  database_configs.each do |db_config|
    next unless db_config.database_tasks?

    yield db_config.name
  end
end
load_schema_current(format = ActiveRecord.schema_format, file = nil, environment = env) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 480
def load_schema_current(format = ActiveRecord.schema_format, file = nil, environment = env)
  each_current_configuration(environment) do |db_config|
    load_schema(db_config, format, file)
  end
  ActiveRecord::Base.establish_connection(environment.to_sym)
end
load_seed() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 495
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
migrate(version = nil) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 256
def migrate(version = nil)
  check_target_version

  scope = ENV["SCOPE"]
  verbose_was, Migration.verbose = Migration.verbose, verbose?

  Base.connection.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

  ActiveRecord::Base.clear_cache!
ensure
  Migration.verbose = verbose_was
end
migrate_status() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 294
def migrate_status
  unless ActiveRecord::Base.connection.schema_migration.table_exists?
    Kernel.abort "Schema migrations table does not exist yet."
  end

  # output
  puts "\ndatabase: #{ActiveRecord::Base.connection_db_config.database}\n\n"
  puts "#{'Status'.center(8)}  #{'Migration ID'.ljust(14)}  Migration Name"
  puts "-" * 50
  ActiveRecord::Base.connection.migration_context.migrations_status.each do |status, version, name|
    puts "#{status.center(8)}  #{version.ljust(14)}  #{name}"
  end
  puts
end
migrations_paths() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 92
def migrations_paths
  @migrations_paths ||= Rails.application.paths["db/migrate"].to_a
end
name() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 112
def name
  @name ||= "primary"
end
prepare_all() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 188
def prepare_all
  seed = false

  each_current_configuration(env) do |db_config|
    ActiveRecord::Base.establish_connection(db_config)

    begin
      # Skipped when no database
      migrate

      if ActiveRecord.dump_schema_after_migration
        dump_schema(db_config, ActiveRecord.schema_format)
      end
    rescue ActiveRecord::NoDatabaseError
      create(db_config)

      if File.exist?(schema_dump_path(db_config))
        load_schema(
          db_config,
          ActiveRecord.schema_format,
          nil
        )
      else
        migrate
      end

      seed = true
    end
  end

  ActiveRecord::Base.establish_connection
  load_seed if seed
end
purge(configuration) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 339
def purge(configuration)
  db_config = resolve_configuration(configuration)
  database_adapter_for(db_config).purge
end
purge_all() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 344
def purge_all
  each_local_configuration { |db_config| purge(db_config) }
end
purge_current(environment = env) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 348
def purge_current(environment = env)
  each_current_configuration(environment) { |db_config| purge(db_config) }
  ActiveRecord::Base.establish_connection(environment.to_sym)
end
raise_for_multi_db(environment = env, command:) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 169
def raise_for_multi_db(environment = env, command:)
  db_configs = configs_for(env_name: environment)

  if db_configs.count > 1
    dbs_list = []

    db_configs.each do |db|
      dbs_list << "#{command}:#{db.name}"
    end

    raise "You're using a multiple database application. To use `#{command}` you must run the namespaced task with a VERSION. Available tasks are #{dbs_list.to_sentence}."
  end
end
register_task(pattern, task) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 79
def register_task(pattern, task)
  @tasks ||= {}
  @tasks[pattern] = task
end
root() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 104
def root
  @root ||= Rails.root
end
schema_dump_path(db_config, format = ActiveRecord.schema_format) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 457
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
schema_file_type(format = ActiveRecord.schema_format) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 447
def schema_file_type(format = ActiveRecord.schema_format)
  case format
  when :ruby
    "schema.rb"
  when :sql
    "structure.sql"
  end
end
schema_up_to_date?(configuration, format = ActiveRecord.schema_format, file = nil) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 390
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)

  ActiveRecord::Base.establish_connection(db_config)

  return false unless ActiveRecord::InternalMetadata.enabled?
  return false unless ActiveRecord::InternalMetadata.table_exists?

  ActiveRecord::InternalMetadata[:schema_sha1] == schema_sha1(file)
end
seed_loader() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 116
def seed_loader
  @seed_loader ||= Rails.application
end
setup_initial_database_yaml() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 140
def setup_initial_database_yaml
  return {} unless defined?(Rails)

  begin
    Rails.application.config.load_database_yaml
  rescue
    unless ActiveRecord.suppress_multiple_database_warning
      $stderr.puts "Rails couldn't infer whether you are using multiple databases from your database.yml and can't generate the tasks for the non-primary databases. If you'd like to use this feature, please simplify your ERB."
    end

    {}
  end
end
structure_dump(configuration, *arguments) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 353
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
structure_load(configuration, *arguments) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 360
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
target_version() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 315
def target_version
  ENV["VERSION"].to_i if ENV["VERSION"] && !ENV["VERSION"].empty?
end
truncate_all(environment = env) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 250
def truncate_all(environment = env)
  configs_for(env_name: environment).each do |db_config|
    truncate_tables(db_config)
  end
end

Private Instance Methods

class_for_adapter(adapter) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 541
def class_for_adapter(adapter)
  _key, task = @tasks.reverse_each.detect { |pattern, _task| adapter[pattern] }
  unless task
    raise DatabaseNotSupported, "Rake tasks not supported by '#{adapter}' adapter"
  end
  task.is_a?(String) ? task.constantize : task
end
configs_for(**options) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 518
def configs_for(**options)
  Base.configurations.configs_for(**options)
end
database_adapter_for(db_config, *arguments) click to toggle source

Create a new instance for the specified db configuration object For classes that have been converted to use db_config objects, pass a ‘DatabaseConfig`, otherwise pass a `Hash`

# File lib/active_record/tasks/database_tasks.rb, line 533
def database_adapter_for(db_config, *arguments)
  klass = class_for_adapter(db_config.adapter)
  converted = klass.respond_to?(:using_database_configurations?) && klass.using_database_configurations?

  config = converted ? db_config : db_config.configuration_hash
  klass.new(config, *arguments)
end
each_current_configuration(environment, name = nil) { |db_config| ... } click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 549
def each_current_configuration(environment, name = nil)
  environments = [environment]
  environments << "test" if environment == "development" && !ENV["SKIP_TEST_DATABASE"] && !ENV["DATABASE_URL"]

  environments.each do |env|
    configs_for(env_name: env).each do |db_config|
      next if name && name != db_config.name

      yield db_config
    end
  end
end
each_local_configuration() { |db_config| ... } click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 562
def each_local_configuration
  configs_for.each do |db_config|
    next unless db_config.database

    if local_database?(db_config)
      yield db_config
    else
      $stderr.puts "This task only modifies local databases. #{db_config.database} is on a remote host."
    end
  end
end
local_database?(db_config) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 574
def local_database?(db_config)
  host = db_config.host
  host.blank? || LOCAL_HOSTS.include?(host)
end
resolve_configuration(configuration) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 522
def resolve_configuration(configuration)
  Base.configurations.resolve(configuration)
end
schema_sha1(file) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 579
def schema_sha1(file)
  OpenSSL::Digest::SHA1.hexdigest(File.read(file))
end
structure_dump_flags_for(adapter) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 583
def structure_dump_flags_for(adapter)
  if structure_dump_flags.is_a?(Hash)
    structure_dump_flags[adapter.to_sym]
  else
    structure_dump_flags
  end
end
structure_load_flags_for(adapter) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 591
def structure_load_flags_for(adapter)
  if structure_load_flags.is_a?(Hash)
    structure_load_flags[adapter.to_sym]
  else
    structure_load_flags
  end
end
truncate_tables(db_config) click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 242
def truncate_tables(db_config)
  ActiveRecord::Base.establish_connection(db_config)

  connection = ActiveRecord::Base.connection
  connection.truncate_tables(*connection.tables)
end
verbose?() click to toggle source
# File lib/active_record/tasks/database_tasks.rb, line 526
def verbose?
  ENV["VERBOSE"] ? ENV["VERBOSE"] != "false" : true
end