ActiveRecord autosave
When ActiveRecord child objects are autosaved in Rails.
Related cards:
Rails: Talking to the database without instantiating ActiveRecord objects
Instantiating ActiveRecord objects comes expensive. To speed up things, you can choose a more direct way to talk to your database: the [ActiveRecord::ConnectionAdapters::DatabaseStatements](http://api.rubyonrails.org/classes/ActiveRecord/Connect...
Rails: When defining scopes with class methods, don't use `self`
Sometimes it is useful to define a named scope by implementing a static method with the scope's name on the scoped class. For instance, when a method should decide which existing scope should be the next link in the scope chain. Take this class fo...
Rails 3 issue: update_all ignores conditions, when :orders and :limit options are supplied
Leads to awesomeness and unicorns when used in production.
ActiveModel: Make Any Ruby Object Feel Like ActiveRecord « Katz Got Your Tongue?
Rails 2.3 has a ton of really nice functionality locked up in monolithic components. I’ve posted quite a bit about how we’ve opened up a lot of that functionality in ActionPack, making it easier to reuse the router, dispatcher, and individual part...
Rails: Configure ActionController to raise when strong params are invalid
Put the line below in the respective env.rb file to make your action controllers raise an ActionController::UnpermittedParameters error when strong params are not valid. This might come in handy when you are implementing an API and you want to...
How Rails and MySQL are handling time zones
When working with times and dates in Rails applications, you need to deal with the following problem:
- In Rails,
Timeobjects have a time zone. You can get the zone name by doingtime_object.zone. - This zone is considered when doing time ca...
Rails: When to use :inverse_of in has_many, has_one or belongs_to associations
When you have two models in a has_many, has_one or belongs_to association, the :inverse_of option in Rails tells ActiveRecord that they're two sides of the same association.
Example with a has_many / belongs_to association:
c...
Rails: Preloading associations in loaded records
Sometimes you want to fetch associations for an ActiveRecord that you already loaded, e.g. when it has deeply nested associations.
Edge Rider gives your models a static method preload_associations. The ...
Save ActiveRecord models without callbacks or validations (in Rails 2 and Rails 3)
Rails 2
You can use
record.send(:update_without_callbacks)
or
record.send(:create_without_callbacks)
This can be used as a lightweight alternative to machinist's make or FactoryGirl's create, when you just need objects...
Merging two arbitrary ActiveRecord scopes
(Rails has a method ActiveRecord::Relation#merge that can merge ActiveRecord scopes. However, its behavior has never been clear, and in Rails 7 it still discards conditions on the same column by the last condition. **We disco...