pg_hashids: Short UIDs

pg_hashids provides a secure way to generate short, unique, non-sequential ids from numbers. The hashes are intended to be small, easy-to-remember identifiers that can be used to obfuscate data (optionally) with a password, alphabet, and salt. For example, you may wish to hide data like user IDs, order numbers, or tracking codes in favor of pg_hashid's unique identifers.

Enable the Extension#

Usage#

Suppose we have a table that stores order information, and we want to give customers a unique identifer without exposing the sequential id column. To do this, we can use pg_hashid's id_encode function.

create table orders (
  id serial primary key,
  description text,
  price_cents bigint
);

insert into orders (description, price_cents)
values ('a book', 9095);

select
  id,
  id_encode(id) as short_id,
  description,
  price_cents
from
  orders;

  id | short_id | description | price_cents
----+----------+-------------+-------------
  1 | jR       | a book      |        9095
(1 row)

To reverse the short_id back into an id, there is an equivalent function named id_decode.

Resources#

• Official pg_hashids documention