method

update

v5.1.7 - Show latest stable - 2 notes - Class: ActiveRecord::Relation

update(id = :all, attributes) public

Updates an object (or multiple objects) and saves it to the database, if validations pass. The resulting object is returned whether the object was saved successfully to the database or not.

Parameters

id - This should be the id or an array of ids to be updated.
attributes - This should be a hash of attributes or an array of hashes.

Examples

# Updates one record
Person.update(15, user_name: 'Samuel', group: 'expert')

# Updates multiple records
people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy" } }
Person.update(people.keys, people.values)

# 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 an 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.

Show source

# File activerecord/lib/active_record/relation.rb, line 409
    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
        records.each { |record| record.update(attributes) }
      else
        if ActiveRecord::Base === id
          raise ArgumentError,             You are passing an instance of ActiveRecord::Base to `update`.            Please pass the id of the object by calling `.id`..squish
        end
        object = find(id)
        object.update(attributes)
        object
      end
    end