How to convert array of ActiveRecord models to CSV?

The following will write the attributes of all users to a file:

CSV.open("path/to/file.csv", "wb") do |csv|
  csv << User.attribute_names
  User.find_each do |user|
    csv << user.attributes.values
  end
end

Similarly you could create a CSV string:

csv_string = CSV.generate do |csv|
  csv << User.attribute_names
  User.find_each do |user|
    csv << user.attributes.values
  end
end