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 few minor changes.
First, add the following to your Gemfile (after the Rails
lines):
# 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
your config/application.rb
file, and not require ActiveRecord
.
The top of your config/application.rb
will probably look something like:
# require 'rails/all'
# Instead of 'rails/all', require these:
%w(
action_cable/engine
action_controller/railtie
action_mailer/railtie
action_view/railtie
active_job/railtie
rails/test_unit/railtie
).each do |railtie|
begin
require railtie
rescue LoadError
end
end
Then you need to get rid of ActiveRecord
and ActiveStorage
configurations, that is if you
didn't generate the new app with -O
(or the long form --skip-active-record
):
For example in a fresh Rails 7
, you would need to remove those lines:
config/environments/development.rb
line 37: # config.active_storage.service = :local
line 54: # config.active_record.migration_error = :page_load
line 57: # config.active_record.verbose_query_logs = true
config/environments/production.rb
line 41: # config.active_storage.service = :local
line 92: # 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: config/initializers/sequel.rb
)
with content:
require "sequel_rails/railties/legacy_model_config"
Rake db:*
mappings are currently not supported in Rails 7, so you'll need to use
the sequel:*
tasks instead. For example, to migrate your database, you'll need to
run rails sequel:migrate
instead of rails db:migrate
.
The rake command to create your db requires that Sequel does not attempt to connect
to load models before creating the db. Add this to your config/application.rb
# config/application.rb
if defined?(Rake.application) && Rake.application.top_level_tasks.include?('sequel:create')
config.sequel.skip_connect = true
end
After those changes, you should be good to go!
sequel-rails
Connection management:
sequel-rails
will initiate the Sequel
connection mechanism based on your
configuration in database.yml
.
Generators:
You can use them just like ActiveRecord
's ones:
Migration:
rails generate migration create_admin_users
# Or
rails generate migration CreateAdminUsers
Model:
rails generate model User email:string
Observer:
rails generate observer User
Session:
rails generate sequel:session_migration
Rake tasks similar to ActiveRecord
, see
Available sequel specific rake tasks
Add some Sequel
and sequel-rails
specific exceptions to ActionDispatch
's rescue_responses
Sequel::Plugins::RailsExtensions::ModelNotFound
is mapped to :not_found
Sequel::NoMatchingRow
is mapped to :not_found
Sequel::ValidationFailed
is mapped to :unprocessable_entity
Sequel::NoExistingObject
is mapped to :unprocessable_entity
Add a i18n_scope
method to Sequel::Model
which respond with "sequel"
.
This is used by ActiveModel
.
Adding Sequel
to 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::Base
so that the sum of SQL queries time
for the current action is reported as DB
for the controller's line in logs.
Provide a ActionDispatch::Session::SequelStore
similar to the
ActiveRecord
one, which stores sessions in database backed by a Sequel
model.
You can configure some options with the usual rails mechanism, in
config/application.rb
and/or in config/environments/*.rb
.
# 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 ActiveRecord
's format.
Here's some examples:
For PostgreSQL:
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
For MySQL:
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
For SQLite:
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/application.rb
config.sequel.after_connect
will 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_connection
will be called after every new connection in connection pool is created. It can be used to run some specific SET
commands on every new connection. It's using default after_connect
hook 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/application.rb
(0.6.2+):
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 Sequel::Model
subclass whose underlying table exists.
SequelStore
to store session in databaseIf 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:
YourAppName::Application.config.session_store :sequel_store
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 config/initializers/session.rb
:
ActionDispatch::Session::SequelStore.session_class = MyCustomSessionModelClass
To get a list of all available rake tasks in your rails3 app, issue the usual in you app's root directory:
rake -T
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] # Drop 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[10])
Improvements have been made by those awesome contributors:
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.