How to generate unique id in MySQL?

Question

I\'m programming a script using PHP and MySQL and I want to get a unique id (consisting of a string: capitals and small letters with numbers) like: gHYtUUi5b.

Answer 1

A programmatic way can be to:

• add a UNIQUE INDEX to the field
• generate a random string in PHP
• loop in PHP ( while( ! DO_THE_INSERT ) )
  • generate another string

Note:

• This can be dirty, but has the advantage to be DBMS-agnostic
• Even if you choose to use a DBMS specific unique ID generator function (UUID, etc) it is a best practice to assure the field HAS to be UNIQUE, using the index
• the loop is statistically not executed at all, it is entered only on insert failure