Change the id of an ActiveRecord record
You most likely never want to do this. But if you do:
Model.update_all({:id => new_id}, {:id => old_id})
Related cards:
ActiveRecord::RecordNotFound errors allow you to query the :name and :id of the model that could not be found
ActiveRecord::RecordNotFound errors provide quite meaningful error messages that can provide some insight on application details. Consider the following:
ActiveRecord::RecordNotFound: Couldn't find Organisation::Membership with 'id'=12 [WHE...
Why has_many :through associations can return the same record multiple times
An association defined with has_many :through will return the same record multiple times if multiple join models for the same record exist (a n:m relation). To prevent this, you need to add ->{ uniq } as second argument to has_many (below Ra...
Change the existing order of an ActiveRecord scope
Use reorder to replace an existing order clause with a new expression.
Use the "paper_trail" gem to track versions of records
paper_trail is an excellent gem to track record versions and changes.
You almost never want to reimplement something like it yourself. If you need to log some extra information, you can add them on top.
It comes with a really good README file...
Allow setting the #id attribute when creating an ActiveRecord
When creating an ActiveRecord with .new, .create or create!, you cannot set the ID attribute (note: When using Machinist's .make you can).
This is because even when you are not using `attr_protected...
RSpec: Change the type of a spec regardless of the folder it lives in
In a Rails application, *_spec.rb files get special treatment depending on the file's directory. E.g. when you put a spec in spec/controllers your examples will have some magic context like controller, post or get that appears out of now...
Security issues with hash conditions in Rails 2 and Rails 3
Find conditions for scopes can be given either as an array (:conditions => ['state = ?', 'draft']) or a hash (:conditions => { 'state' => 'draft' }). The later is nicer to read, but has horrible security implications in some versions of Ru...
How to build the perfect number of blank records for a nested form
When you render a nested form for a Movie which has_many :actors, you want to render the right number of blank Actor forms. The right number means:
- A minimum number of blank forms so the user can add more
Actorsto an existingMovie, ...
Deterministic ordering of records by created_at timestamp
Creating records in specs can be so fast that two records created instantly after one another might have the same created_at timestamp (especially since those timestamps don't have an indefinitely high resolution). When ordering lists by timestamp...
How to change the locale of a PostgreSQL cluster
There may be reasons to change the locale of your Postgres cluster. A popular one is your development system's locale being used by default (which may be annoying). Here is how to do that.
Beware: By following the steps below, you will drop and r...