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

Constants

LOCAL_HOSTS = ["127.0.0.1", "localhost"]
 

Attributes

[W] current_config
[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:structure:dump

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 43
mattr_accessor :structure_dump_flags, instance_accessor: false

structure_load_flags

Extra flags passed to database CLI tool when calling db:structure:load

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 48
mattr_accessor :structure_load_flags, instance_accessor: false

Instance Public methods

cache_dump_filename(namespace)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 413
def cache_dump_filename(namespace)
  filename = if namespace == "primary"
    "schema_cache.yml"
  else
    "#{namespace}_schema_cache.yml"
  end

  ENV["SCHEMA_CACHE"] || File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, filename)
end

charset(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 276
def charset(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).charset
end

charset_current(environment = env, specification_name = spec)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 272
def charset_current(environment = env, specification_name = spec)
  charset ActiveRecord::Base.configurations.configs_for(env_name: environment, spec_name: specification_name).config
end

check_protected_environments!()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 57
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)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 430
def check_schema_file(filename)
  unless File.exist?(filename)
    message = +%{#{filename} doesn't exist yet. Run `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()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 262
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

collation(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 285
def collation(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).collation
end

collation_current(environment = env, specification_name = spec)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 281
def collation_current(environment = env, specification_name = spec)
  collation ActiveRecord::Base.configurations.configs_for(env_name: environment, spec_name: specification_name).config
end

create(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 124
def create(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).create
  $stdout.puts "Created database '#{configuration['database']}'" if verbose?
rescue DatabaseAlreadyExists
  $stderr.puts "Database '#{configuration['database']}' already exists" if verbose?
rescue Exception => error
  $stderr.puts error
  $stderr.puts "Couldn't create '#{configuration['database']}' database. Please check your configuration."
  raise
end

create_all()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 136
def create_all
  old_pool = ActiveRecord::Base.connection_handler.retrieve_connection_pool(ActiveRecord::Base.connection_specification_name)
  each_local_configuration { |configuration| create configuration }
  if old_pool
    ActiveRecord::Base.connection_handler.establish_connection(old_pool.spec.to_hash)
  end
end

create_current(environment = env, spec_name = nil)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 183
def create_current(environment = env, spec_name = nil)
  each_current_configuration(environment, spec_name) { |configuration|
    create configuration
  }
  ActiveRecord::Base.establish_connection(environment.to_sym)
end

current_config(options = {})

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 114
def current_config(options = {})
  options.reverse_merge! env: env
  options[:spec] ||= "primary"
  if options.has_key?(:config)
    @current_config = options[:config]
  else
    @current_config ||= ActiveRecord::Base.configurations.configs_for(env_name: options[:env], spec_name: options[:spec]).config
  end
end

db_dir()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 82
def db_dir
  @db_dir ||= Rails.application.config.paths["db"].first
end

drop(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 190
def drop(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).drop
  $stdout.puts "Dropped database '#{configuration['database']}'" if verbose?
rescue ActiveRecord::NoDatabaseError
  $stderr.puts "Database '#{configuration['database']}' does not exist"
rescue Exception => error
  $stderr.puts error
  $stderr.puts "Couldn't drop database '#{configuration['database']}'"
  raise
end

drop_all()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 202
def drop_all
  each_local_configuration { |configuration| drop configuration }
end

drop_current(environment = env)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 206
def drop_current(environment = env)
  each_current_configuration(environment) { |configuration|
    drop configuration
  }
end

dump_filename(namespace, format = ActiveRecord::Base.schema_format)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 403
def dump_filename(namespace, format = ActiveRecord::Base.schema_format)
  filename = if namespace == "primary"
    schema_file_type(format)
  else
    "#{namespace}_#{schema_file_type(format)}"
  end

  ENV["SCHEMA"] || File.join(ActiveRecord::Tasks::DatabaseTasks.db_dir, filename)
end

dump_schema_cache(conn, filename)

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")

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 452
def dump_schema_cache(conn, filename)
  conn.schema_cache.clear!
  conn.data_sources.each { |table| conn.schema_cache.add(table) }
  open(filename, "wb") { |f| f.write(YAML.dump(conn.schema_cache)) }
end

env()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 102
def env
  @env ||= Rails.env
end

fixtures_path()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 90
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)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 156
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|
    yield db_config.spec_name
  end
end

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

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 423
def load_schema_current(format = ActiveRecord::Base.schema_format, file = nil, environment = env)
  each_current_configuration(environment) { |configuration, spec_name, env|
    load_schema(configuration, format, file, env, spec_name)
  }
  ActiveRecord::Base.establish_connection(environment.to_sym)
end

load_seed()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 438
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()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 232
def migrate
  check_target_version

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

  Base.connection.migration_context.migrate(target_version) do |migration|
    scope.blank? || scope == migration.scope
  end

  ActiveRecord::Base.clear_cache!
ensure
  Migration.verbose = verbose_was
end

migrate_status()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 247
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_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()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 86
def migrations_paths
  @migrations_paths ||= Rails.application.paths["db/migrate"].to_a
end

purge(configuration)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 290
def purge(configuration)
  class_for_adapter(configuration["adapter"]).new(configuration).purge
end

purge_all()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 294
def purge_all
  each_local_configuration { |configuration|
    purge configuration
  }
end

purge_current(environment = env)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 300
def purge_current(environment = env)
  each_current_configuration(environment) { |configuration|
    purge configuration
  }
  ActiveRecord::Base.establish_connection(environment.to_sym)
end

raise_for_multi_db(environment = env, command:)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 169
def raise_for_multi_db(environment = env, command:)
  db_configs = ActiveRecord::Base.configurations.configs_for(env_name: environment)

  if db_configs.count > 1
    dbs_list = []

    db_configs.each do |db|
      dbs_list << "#{command}:#{db.spec_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)

Source: 

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

root()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 98
def root
  @root ||= Rails.root
end

schema_file(format = ActiveRecord::Base.schema_format)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 390
def schema_file(format = ActiveRecord::Base.schema_format)
  File.join(db_dir, schema_file_type(format))
end

schema_file_type(format = ActiveRecord::Base.schema_format)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 394
def schema_file_type(format = ActiveRecord::Base.schema_format)
  case format
  when :ruby
    "schema.rb"
  when :sql
    "structure.sql"
  end
end

schema_up_to_date?(configuration, format = ActiveRecord::Base.schema_format, file = nil, environment = env, spec_name = "primary")

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 341
def schema_up_to_date?(configuration, format = ActiveRecord::Base.schema_format, file = nil, environment = env, spec_name = "primary")
  file ||= dump_filename(spec_name, format)

  return true unless File.exist?(file)

  ActiveRecord::Base.establish_connection(configuration)
  return false unless ActiveRecord::InternalMetadata.table_exists?
  ActiveRecord::InternalMetadata[:schema_sha1] == schema_sha1(file)
end

seed_loader()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 110
def seed_loader
  @seed_loader ||= Rails.application
end

setup_initial_database_yaml()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 144
def setup_initial_database_yaml
  return {} unless defined?(Rails)

  begin
    Rails.application.config.load_database_yaml
  rescue
    $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

spec()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 106
def spec
  @spec ||= "primary"
end

structure_dump(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 307
def structure_dump(*arguments)
  configuration = arguments.first
  filename = arguments.delete_at 1
  class_for_adapter(configuration["adapter"]).new(*arguments).structure_dump(filename, structure_dump_flags)
end

structure_load(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 313
def structure_load(*arguments)
  configuration = arguments.first
  filename = arguments.delete_at 1
  class_for_adapter(configuration["adapter"]).new(*arguments).structure_load(filename, structure_load_flags)
end

target_version()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 268
def target_version
  ENV["VERSION"].to_i if ENV["VERSION"] && !ENV["VERSION"].empty?
end

truncate_all(environment = env)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 226
def truncate_all(environment = env)
  ActiveRecord::Base.configurations.configs_for(env_name: environment).each do |db_config|
    truncate_tables db_config.config
  end
end