Populate 1 Million Records

bulk_record_generator.rb

#-----------IT TAKES AROUND 20 MIN -------------------

## Associations are as follw ::

## Book ---> (has_many) FileSubmissions
## FileSubmission --> (has_one) FileDetail

## Flush all dependent records:
FileDetail.delete_all
FileSubmission.delete_all
Book.delete_all
## Alter tables to generate data always with id 1  and increment it from there
Book.connection.execute "ALTER TABLE `books` AUTO_INCREMENT = 1;"
FileSubmission.connection.execute "ALTER TABLE `books` AUTO_INCREMENT = 1;"
FileDetail.connection.execute "ALTER TABLE `books` AUTO_INCREMENT = 1;"

Book.transaction do 
  start = Time.now.to_i 
  1.upto(1000000) do |i| 
    date = rand(30.day).seconds.ago.to_s :db
     Book.connection.execute "INSERT INTO `books` (`id`,`isbn`, `created_at`, `updated_at`) VALUES (#{i}, #{i}, '#{date}', '#{date}')" ;
     FileSubmission.connection.execute "INSERT INTO `file_submissions` (`id`,`book_id`,`original_name`,`created_at`, `updated_at`) 
           VALUES (#{i}, #{i}, '#{Array.new(12){[*'a'..'z', *'A'..'Z'].sample}.join}', '#{date}', '#{date}')" ;
     FileDetail.connection.execute "INSERT INTO `file_details` (`id`,`file_submission_id`, `created_at`, `updated_at`)
           VALUES (#{i}, #{i}, '#{date}', '#{date}')" ; 
  end time = Time.now.to_i - start
    p "Time taken in seconds #{time}" 
end
#---------------- SCRIPT END ---------------------