Methods
Included Modules
Instance Public methods
each()
Yields an ActiveRecord::Relation
object for each batch of records.
Person.in_batches.each do |relation|
relation.update_all(awesome: true)
end
📝 Source code
# File activerecord/lib/active_record/relation/batches/batch_enumerator.rb, line 62
def each
enum = @relation.to_enum(:in_batches, of: @of, start: @start, finish: @finish, load: false)
return enum.each { |relation| yield relation } if block_given?
enum
end
🔎 See on GitHub
each_record()
Looping through a collection of records from the database (using the all
method, for example) is very inefficient since it will try to instantiate all the objects at once.
In that case, batch processing methods allow you to work with the records in batches, thereby greatly reducing memory consumption.
Person.in_batches.each_record do |person|
person.do_awesome_stuff
end
Person.where("age > 21").in_batches(of: 10).each_record do |person|
person.party_all_night!
end
If you do not provide a block to each_record
, it will return an Enumerator for chaining with other methods:
Person.in_batches.each_record.with_index do |person, index|
person.award_trophy(index + 1)
end
📝 Source code
# File activerecord/lib/active_record/relation/batches/batch_enumerator.rb, line 36
def each_record
return to_enum(:each_record) unless block_given?
@relation.to_enum(:in_batches, of: @of, start: @start, finish: @finish, load: true).each do |relation|
relation.records.each { |record| yield record }
end
end
🔎 See on GitHub