Database

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 identifiers.

Enable the extension

  1. Go to the Database page in the Dashboard.
  2. Click on Extensions in the sidebar.
  3. Search for "pg_hashids" and enable the extension.

Usage

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

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create table orders (
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  id serial primary key,
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  description text,
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  price_cents bigint
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);
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insert into orders (description, price_cents)
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values ('a book', 9095);
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select
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  id,
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  id_encode(id) as short_id,
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  description,
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  price_cents
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from
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  orders;
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  id | short_id | description | price_cents
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----+----------+-------------+-------------
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  1 | jR       | a book      |        9095
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(1 row)

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

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