This gem provides the railtie that allows sequel to hook into Rails (3.x and 4.x) and thus behave like a rails framework component. Just like activerecord does in rails, sequel-rails uses the railtie API to hook into rails. The two are actually hooked into rails almost identically.
The code for this gem was initially taken from the excellent dm-rails project.
Since January 2013, we've become the official maintainers of the gem after brasten proposed us.
Using sequel with Rails (3.x or 4.x) requires a couple minor changes.
First, add the following to your Gemfile (after the
# depending on you database gem "pg" # for PostgreSQL gem "mysql2" # for MySQL gem "sqlite3" # for Sqlite gem "sequel-rails"
... be sure to run "bundle install" if needed!
Secondly, you'll need to require the different Rails components separately in
config/application.rb file, and not require
The top of your
config/application.rb will probably look something like:
# require 'rails/all' # Instead of 'rails/all', require these: require "action_controller/railtie" # require "active_record/railtie" require "action_mailer/railtie" require "sprockets/railtie"
Then you need to get rid of
ActiveRecord configurations, that is if you
didn't generate the new app with
-O (or the long form
For example in a fresh
Rails 4.2.4, you would need to remove those lines:
config/application.rb line 27: config.active_record.raise_in_transactional_callbacks = true
config/environments/development.rb line 23: config.active_record.migration_error = :page_load
config/environments/production.rb line 78: config.active_record.dump_schema_after_migration = false
Starting with sequel-rails 0.4.0.pre3 we don't change default Sequel behaviour
nor include any plugin by default, if you want to get back the previous
behaviour, you can create a new initializer (eg:
After those changes, you should be good to go!
Features provided by
sequel-railswill initiate the
Sequelconnection mechanism based on your configuration in
You can use them just like
rails generate migration create_admin_users # Or rails generate migration CreateAdminUsers
rails generate model User email:string
rails generate observer User
rails generate sequel:session_migration
Rake tasks similar to
ActiveRecord, see Available sequel specific rake tasks
sequel-railsspecific exceptions to
Sequel::Plugins::RailsExtensions::ModelNotFoundis mapped to
Sequel::NoMatchingRowis mapped to
Sequel::ValidationFailedis mapped to
Sequel::NoExistingObjectis mapped to
Sequel::Modelwhich respond with
"sequel". This is used by
ActiveSupport::LogSubscriber. This is what allows you to see SQL queries in the log and also allows us to implement the next item.
Add a hook in
ActionController::Baseso that the sum of SQL queries time for the current action is reported as
DBfor the controller's line in logs.
ActionDispatch::Session::SequelStoresimilar to the
ActiveRecordone, which stores sessions in database backed by a
You can configure some options with the usual rails mechanism, in
config/application.rb and/or in
# Allowed options: :sql, :ruby. config.sequel.schema_format = :sql # Whether to dump the schema after successful migrations. # Defaults to false in production and test, true otherwise. config.sequel.schema_dump = true # These override corresponding settings from the database config. config.sequel.max_connections = 16 config.sequel.search_path = %w(mine public) # Configure whether database's rake tasks will be loaded or not. # # If passed a String or Symbol, this will replace the `db:` namespace for # the database's Rake tasks. # # ex: config.sequel.load_database_tasks = :sequel # will results in `rake db:migrate` to become `rake sequel:migrate` # # Defaults to true config.sequel.load_database_tasks = false # This setting disabled the automatic connect after Rails init config.sequel.skip_connect = true # If you want to use a specific logger config.sequel.logger = MyLogger.new($stdout)
The connection settings are read from the file
config/database.yml and is
expected to be similar to
Here's some examples:
development: adapter: postgresql database: a_database_name user: user_name # Also accept 'username' as key, if both are present 'username' is used password: password host: 10.0.0.2 # Optional port: 5432 # Optional owner: owner_name # Optional encoding: utf8 # Optional, also accept 'charset' as key, if both are present 'encoding' is used (defaults to 'utf8') maintenance_db: template2 # Optional locale: en_US.UTF-8 # Optional, equivalent to setting 'collation' and 'ctype' to the same value collation: en_US.UTF-8 # Optional ctype: en_US.UTF-8 # Optional template: template1 # Optional tablespace: non_default_tablespace_name # Optional max_connections: 20 # Optional, also accept 'pool' as key, if both are present 'max_connections' is used (default to nil, Sequel default is 4) url: "postgres://myuser:mypass@host/somedatabase" # Optional, if present it's passed to `Sequel.connect` with other config as options # If url is not set in config file, environment variable `DATABASE_URL` is used
development: adapter: mysql # Also accept mysql2 database: a_database_name user: user_name # Also accept 'username' as key, if both are present 'username' is used password: password host: 10.0.0.2 # Optional port: 5432 # Optional charset: latin1 # Optional (defaults to 'utf8') collation: latin1_general_ci # Optional (defaults to 'utf8_unicode_ci') url: "mysql://myuser:mypass@host/somedatabase" # Optional, if present it's passed to `Sequel.connect` with other config as options # If url is not set in config file, environment variable `DATABASE_URL` is used
development: adapter: sqlite # Also accept sqlite3 database: db/mydatabase.sqlite # Path to db relative to Rails root
For in memory testing:
development: adapter: sqlite # Also accept sqlite3 database: ":memory:"
If you want to enable plugins for all your models, you should use the
after_connect configuration option in
config.sequel.after_connect = proc do Sequel::Model.plugin :timestamps, update_on_create: true end
This will ensure that these plugins are loaded before any Sequel models are
loaded. Loading plugins into
Sequel::Model after subclasses are already
created is not supported by Sequel. You can also load extensions in
after_connect or perform any custom actions that you need.
Please note: some plugins require a
dataset to work, which means they can't
be added via
Sequel::Model.plugin, they need to be added to a
subclass whose underlying table exists.
SequelStore to store session in database
If you want to store your session in the database you can use the provided
session store backed by a
Sequel model. Edit your
config/initializers/session.rb file and replace the existing code with:
You can then generate a migration for the session table using the provided generator:
rails generate sequel:session_migration rake db:migrate
Optionally if you want to use your own
Sequel model to handle the session,
you can do so in your
ActionDispatch::Session::SequelStore.session_class = MyCustomSessionModelClass
Available sequel specific rake tasks
To get a list of all available rake tasks in your rails3 app, issue the usual in you app's root directory:
or if you don't have hooks in place to run commands with bundle by default:
bundle exec rake -T
Once you do that, you will see the following rake tasks among others. These are the ones that sequel-rails added or replaced:
rake db:create[env] # Create the database defined in config/database.yml for the current Rails.env rake db:create:all # Create all the local databases defined in config/database.yml rake db:drop[env] # Create the database defined in config/database.yml for the current Rails.env rake db:drop:all # Drops all the local databases defined in config/database.yml rake db:force_close_open_connections # Forcibly close any open connections to the test database rake db:migrate # Migrate the database to the latest version rake db:migrate:down # Runs the "down" for a given migration VERSION. rake db:migrate:redo # Rollbacks the database one migration and re migrate up. rake db:migrate:reset # Resets your database using your migrations for the current environment rake db:migrate:up # Runs the "up" for a given migration VERSION. rake db:reset # Drops and recreates the database from db/schema.rb for the current environment and loads the seeds. rake db:schema:dump # Create a db/schema.rb file that can be portably used against any DB supported by Sequel rake db:schema:load # Load a schema.rb file into the database rake db:seed # Load the seed data from db/seeds.rb rake db:setup # Create the database, load the schema, and initialize with the seed data rake db:test:prepare # Prepare test database (ensure all migrations ran, drop and re-create database then load schema). This task can be run in the same invocation as other task (eg: rake db:migrate db:test:prepare).
Note on Patches/Pull Requests
- Fork the project.
- Make your feature addition or bug fix.
- Add specs for it. This is important so I don't break it in a future version unintentionally.
- Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
- Send me a pull request. Bonus points for topic branches.
The sequel-rails team
- Jonathan Tron (JonathanTron) - Current maintainer
- Joseph Halter (JosephHalter) - Current maintainer
- Brasten Sager (brasten) - Project creator
Improvements have been made by those awesome contributors:
- Benjamin Atkin (benatkin)
- Gabor Ratky (rgabo)
- Joshua Hansen (binarypaladin)
- Arron Washington (radicaled)
- Thiago Pradi (tchandy)
- Sascha Cunz (scunz)
- Brian Donovan (eventualbuddha)
- Jack Danger Canty (JackDanger)
- Ed Ruder (edruder)
- Rafał Rzepecki (dividedmind)
- Sean Sorrell (rudle)
- Saulius Grigaliunas (sauliusg)
- Jacques Crocker (railsjedi)
- Eric Strathmeyer (strathmeyer)
- Jan Berdajs (mrbrdo)
- Robert Payne (robertjpayne)
- Kevin Menard (nirvdrum)
- Chris Heisterkamp (cheister)
- Tamir Duberstein (tamird)
- shelling (shelling)
- a3gis (a3gis)
- Andrey Chernih (andreychernih)
- Nico Rieck (gix)
- Alexander Birkner (BirknerAlex)
- kr3ssh (kressh)
- John Anderson (djellemah)
- Larivact (Larivact)
- Jan Berdajs (mrbrdo)
The dm-rails team wrote most of the original code, I just sequel-ized it, but since then most of it has been either adapted or rewritten.
Copyright (c) 2010-2013 The sequel-rails team. See LICENSE for details.