---
title: "Rails 5 Updating records in AR Relation"
description:
  "Rails 5 modified the ActiveRecord::Relation#update method to now support
  update on the relation. It also runs callbacks and validations on the records."
canonical_url: "https://www.bigbinary.com/blog/rails-5-allows-updating-relation-objects-along-with-callbacks-and-validations"
markdown_url: "https://www.bigbinary.com/blog/rails-5-allows-updating-relation-objects-along-with-callbacks-and-validations.md"
---

# Rails 5 Updating records in AR Relation

Rails 5 modified the ActiveRecord::Relation#update method to now support update
on the relation. It also runs callbacks and validations on the records.

- Author: Mohit Natoo
- Published: June 10, 2016
- Categories: Rails 5, Rails

The `update_all` method when called on an `ActiveRecord::Relation` object
updates all the records without invoking any callbacks and validations on the
records being updated.

Rails 5 supports
[update method on an ActiveRecord::Relation object](https://github.com/rails/rails/pull/11898)
that runs callbacks and validations on all the records in the relation.

```ruby

people = Person.where(country: 'US')
people.update(language: 'English', currency: 'USD')

```

Internally, the above code runs `update` method on each `Person` record whose
country is `'US'`.

Let's see what happens when `update` is called on a relation in which
validations fail on few records.

We have a Note model. For simplicity let's add a validation that `note_text`
field cannot be blank for first three records.

```ruby
class Note < ApplicationRecord
  validate :valid_note

  def valid_note
   errors.add(:note_text, "note_text is blank") if id <= 3 && note_text.blank?
  end
end
```

Now let's try and update all the records with blank `note_text`.

```ruby

 > Note.all.update(note_text: '')
  Note Load (0.3ms)  SELECT `notes`.* FROM `notes`
   (0.1ms)  BEGIN
   (0.1ms)  ROLLBACK
   (0.1ms)  BEGIN
   (0.1ms)  ROLLBACK
   (0.1ms)  BEGIN
   (0.1ms)  ROLLBACK
   (0.1ms)  BEGIN
  SQL (2.9ms)  UPDATE `notes` SET `note_text` = '', `updated_at` = '2016-06-16 19:42:21' WHERE `notes`.`id` = 3
   (0.7ms)  COMMIT
   (0.1ms)  BEGIN
  SQL (0.3ms)  UPDATE `notes` SET `note_text` = '', `updated_at` = '2016-06-16 19:42:21' WHERE `notes`.`id` = 4
   (1.2ms)  COMMIT
   (0.1ms)  BEGIN
  SQL (0.3ms)  UPDATE `notes` SET `note_text` = '', `updated_at` = '2016-06-16 19:42:21' WHERE `notes`.`id` = 5
   (0.3ms)  COMMIT
   (0.1ms)  BEGIN
  SQL (3.4ms)  UPDATE `notes` SET `note_text` = '', `updated_at` = '2016-06-16 19:42:21' WHERE `notes`.`id` = 6
   (0.2ms)  COMMIT

 => [#<Note id: 1, user_id: 1, note_text: "", created_at: "2016-06-03 10:02:54", updated_at: "2016-06-16 19:42:21">,
 #<Note id: 2, user_id: 1, note_text: "", created_at: "2016-06-03 10:03:54", updated_at: "2016-06-16 19:42:21">,
 #<Note id: 3, user_id: 1, note_text: "", created_at: "2016-06-03 12:35:20", updated_at: "2016-06-03 12:35:20">,
 #<Note id: 4, user_id: 1, note_text: "", created_at: "2016-06-03 14:15:15", updated_at: "2016-06-16 19:14:20">,
 #<Note id: 5, user_id: 1, note_text: "", created_at: "2016-06-03 14:15:41", updated_at: "2016-06-16 19:42:21">,
 #<Note id: 6, user_id: 1, note_text: "", created_at: "2016-06-03 14:16:20", updated_at: "2016-06-16 19:42:21">]

```

We can see that failure of validations on records in the relation does not stop
us from updating the valid records.

Also the return value of update on AR Relation is an array of records in the
relation. We can see that the attributes in these records hold the values that
we wanted to have after the update.

For example in the above mentioned case, we can see that in the returned array,
the records with ids 1, 2 and 3 have blank `note_text` values even though those
records weren't updated.

Hence we may not be able to rely on the return value to know if the update is
successful on any particular record.

For scenarios where running validations and callbacks is not important and/or
where performance is a concern it is advisable to use `update_all` method
instead of `update` method.

## Links

- [Human page](https://www.bigbinary.com/blog/rails-5-allows-updating-relation-objects-along-with-callbacks-and-validations)