Rails - Build a CSV and send it though email

users_generator.rb

require 'csv'

def generate_users
  query = "SELECT first_name, last_name FROM users"
  sanitized_query = ActiveRecord::Base.sanitize_sql_array([query])
  result = ActiveRecord::Base.connection.execute(sanitized_query).values

  csv_string = CSV.generate do |csv| 
    csv << ["first_name", "last_name"]
    result.map { |row| csv << row } 
  end

  mailer = ActionMailer::Base.new
  mailer.attachments["result.csv"] = csv_string
  mailer.mail(
    from: "[email protected]", 
    to: ["[email protected]"], 
    subject: "Users from #{Date.today.strftime('%d-%m-%Y')}", 
    body: "See attached"
  )
  mailer.message.deliver
end

generate_users