Re: Generating random unique alphanumeric IDs

The following is the obvious PGSQL code, you'd obviously need something

else to stop duplicates.

 SELECT array_to_string(array((
   SELECT SUBSTRING('abcdefghjklmnpqrstuvwxyz23456789'
                    FROM mod((random()*32)::int, 32)+1 FOR 1)
   FROM generate_series(1,5))),'');

As this only generates five characters and each character can be one of
32 values, you've got about 33554432 choices and you'd have a 50% chance
of getting a duplicate after 7240 values.  This assumes I wrote the
above code correctly.  It's also not amazing because PG's random number
generator is defined to return a value between 0 and 1 inclusive, it's
generally much more useful if it runs from 0 to less than 1 and would
mean that I wouldn't need the "mod" above and would remove the (slight)
biasing towards choosing 'a'.