How to generate unique random string with ServerConnect

Hi all,

I have a table “pages”, containing columns “id” and “slug”.
User can create a new Page and I need to automatically create a unique “slug” for it. Here is an example:
pages.cc/X1Af9M
“Slug” is 6 chars alphanumeric string. Every page is unique, so duplicates are not allowed.

What is the best and efficient way of doing it on ServerConnect side? How to generate this profile of string and how to ensure uniqueness without shooting duplicate errors to the user.