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

As a customer I would be happy with:

year-month-day/short_uid

for example:

2009-07-27/KT1E

It gives room for about 33^4 ~ 1mln orders a day.

Answer 2

I'd rather submit the number 347 and get great customer service at a smaller personable website than: G-84e38wRD-45OM at the mega-site and be ignored for a week.

You would not want this as a system id or part of a link, but as a user-friendly number it works.

Answer 3

Rather than generating and storing a number, you might try creating an encrypted version that would not reveal the number of orders in the system. Here's an article on exactly that.

Answer 4

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.

Answer 5

Ok, how about this one?

Sequentially, starting at some number (2468) and add some other number to it, say the day of the month that the order was placed.

The number always increases (until you exceed the capacity of the integer type, but by then you probably don't care, as you will be incredibly successful and will be sipping margaritas in some far-off island paradise). It's simple enough to implement, and it mixes things up enough to throw off any guessing as to how many orders you have.

Answer 6

You could do it like a postal code: 2b2 b2b

That way it has some kind of checksum (not really, but at least you know it's wrong if there are 2 consecutive numbers or letters). It's easy to read out over the phone, and it doesn't give an indication of how many orders are in the system.