# class ActiveRecord::Batches::BatchEnumerator

### Public Instance Methods

each() { |relation| ... } click to toggle source

Yields an ActiveRecord::Relation object for each batch of records.

    Person.in_batches.each do |relation|
      relation.update_all(awesome: true)
    end

    # File lib/active_record/relation/batches/batch_enumerator.rb, line 60
    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

each_record() { |record| ... } click to toggle source

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

    # File lib/active_record/relation/batches/batch_enumerator.rb, line 34
    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