Dump Active Record Relation to CSV

dump_relation.rb

require 'csv'

def dump_relation(file_name, relation)
  File.open(file_name, 'w') do |file|
     # Load the data once
    records = relation.to_a
    # Write headers
    file.puts records.first.attributes.keys.to_csv
    # Write records
    records.each { |record| file.puts record.attributes.values.to_csv }
  end
  true
end

def dump_big_relation(file_name, relation)
  File.open(file_name, 'w') do |file|
    # Write headers
    file.puts relation.first.attributes.keys.to_csv
    # Write records
    records.find_each { |record| file.puts record.attributes.values.to_csv }
  end
  true
end