Rails 3: Generate unique codes (coupons)

Question

What\'s the best way to generate unique codes to use as coupon codes?

Thanks.

Answer 1

You can do something like this too:

chars = ('a'..'z').to_a + ('A'..'Z').to_a
def String.random_alphanumeric(size=16)
    (0...size).collect { chars[Kernel.rand(chars.length)] }.join
end

But then you would have to compare against a database to make sure it is not used yet.