# 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 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')

### Constants

LOCAL_HOSTS

### Attributes

current_config[W]
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:structure:dump

    # File lib/active_record/tasks/database_tasks.rb, line 39
    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:structure:load

    # File lib/active_record/tasks/database_tasks.rb, line 44
    mattr_accessor :structure_load_flags, instance_accessor: false

### Public Instance Methods

charset(*arguments) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 183
    def charset(*arguments)
      configuration = arguments.first
      class_for_adapter(configuration["adapter"]).new(*arguments).charset
    end

charset_current(environment = env) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 179
    def charset_current(environment = env)
      charset ActiveRecord::Base.configurations[environment]
    end

check_protected_environments!() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 53
    def check_protected_environments!
      unless ENV["DISABLE_DATABASE_ENVIRONMENT_CHECK"]
        current = ActiveRecord::Migrator.current_environment
        stored  = ActiveRecord::Migrator.last_stored_environment

        if ActiveRecord::Migrator.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 260
    def check_schema_file(filename)
      unless File.exist?(filename)
        message = %Q{#{filename} doesn't exist yet. Run `rails db:migrate` to create it, then try again.}
        message << %Q{ 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

collation(*arguments) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 192
    def collation(*arguments)
      configuration = arguments.first
      class_for_adapter(configuration["adapter"]).new(*arguments).collation
    end

collation_current(environment = env) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 188
    def collation_current(environment = env)
      collation ActiveRecord::Base.configurations[environment]
    end

create(*arguments) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 115
    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 database for #{configuration.inspect}"
      raise
    end

create_all() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 127
    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) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 135
    def create_current(environment = env)
      each_current_configuration(environment) { |configuration|
        create configuration
      }
      ActiveRecord::Base.establish_connection(environment.to_sym)
    end

current_config(options = {}) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 106
    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() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 78
    def db_dir
      @db_dir ||= Rails.application.config.paths["db"].first
    end

drop(*arguments) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 142
    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() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 154
    def drop_all
      each_local_configuration { |configuration| drop configuration }
    end

drop_current(environment = env) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 158
    def drop_current(environment = env)
      each_current_configuration(environment) { |configuration|
        drop configuration
      }
    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 282
    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() click to toggle source

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

fixtures_path() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 86
    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) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 253
    def load_schema_current(format = ActiveRecord::Base.schema_format, file = nil, environment = env)
      each_current_configuration(environment) { |configuration|
        load_schema configuration, format, file
      }
      ActiveRecord::Base.establish_connection(environment.to_sym)
    end

load_seed() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 268
    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() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 164
    def migrate
      raise "Empty VERSION provided" if ENV["VERSION"] && ENV["VERSION"].empty?

      verbose = ENV["VERBOSE"] ? ENV["VERBOSE"] == "true" : true
      version = ENV["VERSION"] ? ENV["VERSION"].to_i : nil
      scope = ENV["SCOPE"]
      verbose_was, Migration.verbose = Migration.verbose, verbose
      Migrator.migrate(migrations_paths, version) do |migration|
        scope.blank? || scope == migration.scope
      end
      ActiveRecord::Base.clear_cache!
    ensure
      Migration.verbose = verbose_was
    end

migrations_paths() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 82
    def migrations_paths
      @migrations_paths ||= Rails.application.paths["db/migrate"].to_a
    end

purge(configuration) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 197
    def purge(configuration)
      class_for_adapter(configuration["adapter"]).new(configuration).purge
    end

purge_all() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 201
    def purge_all
      each_local_configuration { |configuration|
        purge configuration
      }
    end

purge_current(environment = env) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 207
    def purge_current(environment = env)
      each_current_configuration(environment) { |configuration|
        purge configuration
      }
      ActiveRecord::Base.establish_connection(environment.to_sym)
    end

register_task(pattern, task) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 69
    def register_task(pattern, task)
      @tasks ||= {}
      @tasks[pattern] = task
    end

root() click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 94
    def root
      @root ||= Rails.root
    end

schema_file(format = ActiveRecord::Base.schema_format) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 244
    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() click to toggle source

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

structure_dump(*arguments) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 214
    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) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 220
    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

### Private Instance Methods

class_for_adapter(adapter) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 290
    def class_for_adapter(adapter)
      key = @tasks.keys.detect { |pattern| adapter[pattern] }
      unless key
        raise DatabaseNotSupported, "Rake tasks not supported by '#{adapter}' adapter"
      end
      @tasks[key]
    end

each_current_configuration(environment) { |configuration| ... } click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 298
    def each_current_configuration(environment)
      environments = [environment]
      environments << "test" if environment == "development"

      configurations = ActiveRecord::Base.configurations.values_at(*environments)
      configurations.compact.each do |configuration|
        yield configuration unless configuration["database"].blank?
      end
    end

each_local_configuration() { |configuration| ... } click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 308
    def each_local_configuration
      ActiveRecord::Base.configurations.each_value do |configuration|
        next unless configuration["database"]

        if local_database?(configuration)
          yield configuration
        else
          $stderr.puts "This task only modifies local databases. #{configuration['database']} is on a remote host."
        end
      end
    end

local_database?(configuration) click to toggle source

    # File lib/active_record/tasks/database_tasks.rb, line 320
    def local_database?(configuration)
      configuration["host"].blank? || LOCAL_HOSTS.include?(configuration["host"])
    end