unique reservation code

[jrahma]

Hi,

I have a booking system using MySQL backend.

I need to generate a unique reservation code in reservato_code varchar field.

the code sohould be random 6 digits aphanumeric

thanks,
Jassim

[Weedpacket]

Good for you.

[NogDog]

Well, random <> unique, so first you need to decide what your true requirements are in this regard.

Based on what you've stated, you could build a table of all possible 6-digit numbers, then select a random unused value when you need it (and mark it as used).

[NogDog]

Of course, the much simpler/cleaner solution is to forget about the random part (why does an order number need to be random?), and just use an auto-increment integer primary key as your order number, perhaps starting the numbering at 100000 so that you don't have to worry about leading zeroes. (With the added benefit you don't have to change anything -- at least on the data side -- when you get your millionth reservation. 🙂 )