This gem provides the railtie that allows sequel to hook into Rails (5.2.x, 6.x, 7.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.
This was originally a fork of brasten's sequel-rails that has been updated to support newer versions of rails.
Since January 2013, we've become the official maintainers of the gem after brasten proposed us.
Using sequel with Rails (5.2.x, 6.x, 7.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 "active_model/railtie" require "active_job/railtie" # require "active_record/railtie" require "action_controller/railtie" require "action_mailer/railtie" require "action_view/railtie" require "action_cable/engine" require "sprockets/railtie" require "rails/test_unit/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 126.96.36.199, you would need to remove those lines:
config/initializers/new_framework_defaults.rb line 18: Rails.application.config.active_record.belongs_to_required_by_default = true
config/environments/development.rb line 38: config.active_record.migration_error = :page_load
config/environments/production.rb line 85: 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 # Allowed options: true, false, default false config.sequel.allow_missing_migration_files = true # 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 # Configure if Sequel should try to 'test' the database connection in order # to fail early config.sequel.test_connect = true # Configure what should happend after SequelRails will create new connection with Sequel (applicable only for the first new connection) # config.sequel.after_connect = proc do # Sequel::Model.plugin :timestamps, update_on_create: true # Sequel::Model.db.extension :pg_array, :pg_hstore # database specific extension # Sequel.extension :pg_hstore_ops # sequel specific extension # end # Configure what should happend after new connection in connection pool is created (applicable only for all connections) # to fail early # config.sequel.after_new_connection = proc do |db| # db.execute('SET statement_timeout = 30000;') # end # 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:"
There are 2 options how to set after_connect hooks in
config.sequel.after_connectwill be called only on the first new connection. It can be used for enabling plugins or to set some global sequel settings.
config.sequel.after_connect = proc do Sequel::Model.plugin :timestamps, update_on_create: true Sequel::Model.db.extension :pg_array, :pg_hstore # database specific extension Sequel.extension :pg_hstore_ops # sequel specific extension end
config.sequel.after_new_connectionwill be called after every new connection in connection pool is created. It can be used to run some specific
SETcommands on every new connection. It's using default
after_connecthook in sequel. https://sequel.jeremyevans.net/rdoc/classes/Sequel/ConnectionPool.html#attribute-i-after_connect
config.sequel.after_new_connection = proc do |db| db.execute('SET statement_timeout = 30000;') end
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). rake db:sessions:clear # Delete all sessions from the database rake db:sessions:trim[threshold] # Delete all sessions older than `threshold` days (default to 30 days, eg: rake db:session:trim)
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)
- Lukas Fittl (@lfittl)
- Jordan Owens (@jkowens)
- Pablo Herrero (@pabloh)
- Henre Botha (@henrebotha)
- Mohammad Satrio (@tyok)
- Gencer W. Genç (@gencer)
- Steve Hoeksema (@steveh)
- Jester (@Jesterovskiy)
- ckoenig (@ckoenig)
- Rolf Timmermans (@rolftimmermans)
- Olivier Lacan (@olivierlacan)
- Dustin Byrne (@dsbyrne)
- Michael Coyne (@mjc-gh)
- p-leger (@p-leger)
- Semyon Pupkov (@artofhuman)
- Ben Koshy (@BKSpurgeon)
- Janko Marohnić (@janko)
- Adrián Mugnolo (@xymbol)
- Ivan (@AnotherRegularDude)
- kamilpavlicko (@kamilpavlicko)
- Stefan Vermaas (@stefanvermaas)
- Yuri Smirnov (@tycooon)
- Mickael Kurmann (@elbouillon)
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) 2010-2022 The sequel-rails team. See LICENSE for details.