How to generate a random, unique, alphanumeric ID of length N in Postgres 9.6+?

Question

I\'ve seen a bunch of different solutions on StackOverflow that span many years and many Postgres versions, but with some of the newer features like gen_random_bytes I want

Answer 1

I'm looking for something that gives me "shortcodes" (similar to what Youtube uses for video IDs) that are as short as possible while still containing only alphanumeric characters.

This is a fundamentally different question from what you first asked. What you want here then is to put a serial type on the table, and to use hashids.org code for PostgreSQL.

• This returns 1:1 with the unique number (serial)
• Never repeats or has a chance of collision.
• Also base62 [a-zA-Z0-9]

Code looks like this,

SELECT id, hash_encode(foo.id)
FROM foo; -- Result: jNl for 1001

SELECT hash_decode('jNl') -- returns 1001

This module also supports salts.