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 Rake tasks 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 41
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 46
mattr_accessor :structure_load_flags, instance_accessor: false

Instance Public methods

charset(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 194
def charset(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).charset
end

charset_current(environment = env)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 190
def charset_current(environment = env)
  charset ActiveRecord::Base.configurations[environment]
end

check_protected_environments!()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 55
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 271
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.}.dup
    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 180
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 203
def collation(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).collation
end

collation_current(environment = env)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 199
def collation_current(environment = env)
  collation ActiveRecord::Base.configurations[environment]
end

create(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 117
def create(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).create
  $stdout.puts "Created database '#{configuration['database']}'"
rescue DatabaseAlreadyExists
  $stderr.puts "Database '#{configuration['database']}' already exists"
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 129
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)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 137
def create_current(environment = env)
  each_current_configuration(environment) { |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 108
def current_config(options = {})
  options.reverse_merge! env: env
  if options.has_key?(:config)
    @current_config = options[:config]
  else
    @current_config ||= ActiveRecord::Base.configurations[options[:env]]
  end
end

db_dir()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 80
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 144
def drop(*arguments)
  configuration = arguments.first
  class_for_adapter(configuration["adapter"]).new(*arguments).drop
  $stdout.puts "Dropped database '#{configuration['database']}'"
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 156
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 160
def drop_current(environment = env)
  each_current_configuration(environment) { |configuration|
    drop configuration
  }
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 293
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 100
def env
  @env ||= Rails.env
end

fixtures_path()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 88
def fixtures_path
  @fixtures_path ||= if ENV["FIXTURES_PATH"]
    File.join(root, ENV["FIXTURES_PATH"])
  else
    File.join(root, "test", "fixtures")
  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 264
def load_schema_current(format = ActiveRecord::Base.schema_format, file = nil, environment = env)
  each_current_configuration(environment) { |configuration, configuration_environment|
    load_schema configuration, format, file, configuration_environment
  }
  ActiveRecord::Base.establish_connection(environment.to_sym)
end

load_seed()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 279
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 166
def migrate
  check_target_version

  verbose = ENV["VERBOSE"] ? ENV["VERBOSE"] != "false" : true
  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

migrations_paths()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 84
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 208
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 212
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 218
def purge_current(environment = env)
  each_current_configuration(environment) { |configuration|
    purge configuration
  }
  ActiveRecord::Base.establish_connection(environment.to_sym)
end

register_task(pattern, task)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 71
def register_task(pattern, task)
  @tasks ||= {}
  @tasks[pattern] = task
end

root()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 96
def root
  @root ||= Rails.root
end

schema_file(format = ActiveRecord::Base.schema_format)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 255
def schema_file(format = ActiveRecord::Base.schema_format)
  case format
  when :ruby
    File.join(db_dir, "schema.rb")
  when :sql
    File.join(db_dir, "structure.sql")
  end
end

seed_loader()

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 104
def seed_loader
  @seed_loader ||= Rails.application
end

structure_dump(*arguments)

Source: 

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 225
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 231
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 186
def target_version
  ENV["VERSION"].to_i if ENV["VERSION"] && !ENV["VERSION"].empty?
end