From 5ef713c53c49b54615be9b5a400ac5810b404e76 Mon Sep 17 00:00:00 2001 From: Prathamesh Sonpatki Date: Thu, 15 Aug 2013 12:43:25 +0530 Subject: Allow ActiveRecord::Relation#update to run on result of a relation with callbacks and validations - Right now, there is no method to update multiple records with validations and callbacks. - Changed the behavior of existing `update` method so that when `id` attribute is not given and the method is called on an `Relation` object, it will execute update for every record of the `Relation` and will run validations and callbacks for every record. - Added test case for validating that the callbacks run when `update` is called on a `Relation`. - Changed test_create_columns_not_equal_attributes test from persistence_test to include author_name column on topics table as it it used in before_update callback. - This change introduces performance issues when a large number of records are to be updated because it runs UPDATE query for every record of the result. The `update_all` method can be used in that case if callbacks are not required because it will only run single UPDATE for all the records. --- activerecord/lib/active_record/relation.rb | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'activerecord/lib/active_record/relation.rb') diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb index daafb0b645..5ca28033bf 100644 --- a/activerecord/lib/active_record/relation.rb +++ b/activerecord/lib/active_record/relation.rb @@ -362,9 +362,21 @@ module ActiveRecord # # Updates multiple records # people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy" } } # Person.update(people.keys, people.values) - def update(id, attributes) + # + # # Updates multiple records from the result of a relation + # people = Person.where(group: 'expert') + # people.update(group: 'masters') + # + # Note: Updating a large number of records will run a + # UPDATE query for each record, which may cause a performance + # issue. So if it is not needed to run callbacks for each update, it is + # preferred to use update_all for updating all records using + # a single query. + def update(id = :all, attributes) if id.is_a?(Array) id.map.with_index { |one_id, idx| update(one_id, attributes[idx]) } + elsif id == :all + to_a.each { |record| record.update(attributes) } else object = find(id) object.update(attributes) -- cgit v1.2.3