CODEWITHSUNDEEP
ruby-on-railspostgresqlactiverecordruby-on-rails-4heroku
yaru
yaru

Reputation: 1310

Is there a guarantee that ActiveRecord returns objects ordered by ID?

My project is hosted on Heroku. I was surprised when Room.all method returned objects with first object with ID 2 and only then a second object with ID 1. I thought that there were some sort of guarantee that objects are returned already ordered by ID. Should I always call Room.all.order(:id) instead of regular all method?

irb(main):002:0> Room.all
=> #<ActiveRecord::Relation [
    #<Room id: 2, color: "rgb(83, 180, 83)", status: "Status #2", created_at: "2014-10-11 14:14:02", updated_at: "2014-10-11 14:18:19">, 
    #<Room id: 1, color: "rgb(0, 96, 255)", status: "Status #3", created_at: "2014-10-11 14:14:02", updated_at: "2014-10-11 14:18:30">
  ]>

Upvotes: 1

Views: 260

Answers (1)

Pavling
Pavling

Reputation: 3963

Nope. Room.all just ends up with the SQL SELECT * FROM rooms; - no order is there. In this event, the order of the records is determined by the database (for instance, in PostgreSQL, I notice it returns me the most recently updated records last).

If you want to ensure there's an order when you call .all, add a default scope which adds it:

default_scope order('rooms.id ASC')

Upvotes: 3

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