Best way to generate order numbers for an online store?

Question

Every order in my online store has a user-facing order number. I\'m wondering the best way to generate them. Criteria include:

• Short
• Easy to say over the

Answer 1

Douglas Crockford's Base32 Encoding works superbly well for this.

http://www.crockford.com/wrmg/base32.html

Store the ID itself in your database as an auto-incrementing integer, starting at something suitably large like 100000, and simply expose the encoded value to the customer/interface.

5 characters will see you through your first ~32 million orders, whilst performing very well and satisfying most of these requirements. It doesn't allow for the exclusion of similar sounding characters though.