Generating unique token on the fly with Rails

Question

I want to generate a token in my controller for a user in the \"user_info_token\" column. However, I want to check that no user currently has that token. Would this code suffice

Answer 1

The cleanest solution I found:

@seller.user_info_token = loop do
  token = SecureRandom.urlsafe_base64
  break token unless User.exists?(user_info_token: token)
end

And something very clean but with potential duplicates (very few though):

@seller.user_info_token = SecureRandom.uuid

Random UUID probability of duplicates

Edit: of course, add a unique index to your :user_info_token. It will be much quicker to search for a user with the same token and it will raise an exception if by chance, 2 users are saved at the exact same moment with the exact same token!