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TypeID SQL

A SQL implementation of TypeID using PostgreSQL.

License: Apache 2.0

TypeIDs are a modern, type-safe, globally unique identifier based on the upcoming UUIDv7 standard. They provide a ton of nice properties that make them a great choice as the primary identifiers for your data in a database, APIs, and distributed systems. Read more about TypeIDs in their spec.

This particular implementation demonstrates how to use TypeIDs in a postgres database.

Installation

To use typeids in your Postgres instance, you'll need define all the appropriate types and functions by running the SQL scripts in this repo.

We recommend copying the SQL scripts into your migrations directory and using the migration tool of your choice. For example, Flyway, or Liquibase.

Note that this repo is using Supabase as a way to easily start a Postgres instance for development and testing, but you do not need to use Supabase for this implementation to work – simply use the Postgres instance of your choice.

Usage

Once you've installed the TypeID types and functions in your Postgres instance, you have two options on how to encode TypeIDs in your database.

1. Text-based encoding

This encoding is more inefficient than the alternative, but it's very straight-forward to understand, it's easy to debug by simply inspecting the contents of your tables, and it works well with other tools you might be using to inspect your database.

To use it:

  • Declare your id column using the text type.
  • Use the typeid_generate_text function to generate new default values.
  • Use the typeid_check_text to enforce all strings in the column are valid typeids.

Example:

-- Define a `users` table that uses `user_id` as its primary key.
-- We use the `typeid_generate_text` function to randomly generate a new typeid of the
-- correct type for each user.
-- We also recommend adding the check constraint to the column
CREATE TABLE users (
    "id" text not null default typeid_generate_text('user') CHECK (typeid_check_text(id, 'user')),
    "name" text,
    "email" text
);

-- Now we can insert new users and have the `id` column automatically generated.
INSERT INTO users ("name", "email") VALUES ('Alice P. Hacker', '[email protected]');
SELECT id FROM users;
-- Result:
-- "user_01hfs6amkdfem8sb6b1xmg7tq7"

-- Insert a user with a specific typeid that might have been generated elsewhere:
INSERT INTO users ("id", "name", "email")
VALUES ('user_01h455vb4pex5vsknk084sn02q', 'Ben Bitdiddle', '[email protected]');

-- To retrieve the ids as encoded strings, just use the column:
SELECT id AS id, "name", "email" FROM users;

-- You can also use filter in a WHERE clause to filter by typeid:
SELECT typeid_print(id) AS id, "name", "email" FROM users
WHERE id = 'user_01h455vb4pex5vsknk084sn02q';

2. UUID-based encoding using compound types

In this approach, we internally encode typeids as a (prefix, uuid) tuple. The sql files in this library provide a predefined typeid type to represent said tuples.

The advantage of this approach is that it is a more efficient encoding because we store the uuid portion of the typeid using the native uuid type.

The disadvanage is that it is harder to work with and debug.

If performance is a primary concern of yours, also consider using the native postgres extension for typeid, which exposes typeids as a "built-in" type.

To define a new typeid using this encoding, you can use the typeid_check function:

-- Define a `user_id` type, which is a typeid with type prefix "user".
-- Using `user_id` throughout our schema, gives us type safety by guaranteeing
-- that the type prefix is always "user".
CREATE DOMAIN user_id AS typeid CHECK (typeid_check(value, 'user'));

You can now use the newly defined type in your tables. The typeid_generate function makes it possible to automatically a new random typeid for each row:

-- Define a `users` table that uses `user_id` as its primary key.
-- We use the `typeid_generate` function to randomly generate a new typeid of the
-- correct type for each user.
CREATE TABLE users (
    "id" user_id not null default typeid_generate('user'),
    "name" text,
    "email" text
);

-- Now we can insert new users and have the `id` column automatically generated.
INSERT INTO users ("name", "email") VALUES ('Alice P. Hacker', '[email protected]');

Querying

To make it easy to query typeid tuples using the standard string representation, we provide two convenience functions: typeid_parse and typeid_print, which convert to and from the standard string representation.

Example:

-- Insert a user with a specific typeid that might have been generated elsewhere:
INSERT INTO users ("id", "name", "email")
VALUES (typeid_parse('user_01h455vb4pex5vsknk084sn02q'), 'Ben Bitdiddle', '[email protected]');

-- To retrieve the ids as encoded strings, use the `typeid_print` function:
SELECT typeid_print(id) AS id, "name", "email" FROM users;

-- You can also use `typeid_parse` in a WHERE clause to filter by typeid:
SELECT typeid_print(id) AS id, "name", "email" FROM users
WHERE id = typeid_parse('user_01h455vb4pex5vsknk084sn02q');

(Optional) Operator overload

If you'd like to be able to do the following:

-- Query directly from the DB with a serialized typeid
SELECT * FROM users u WHERE u.id = 'user_01h455vb4pex5vsknk084sn02q';

-- Result:
-- "(user,018962e7-3a6d-7290-b088-5c4e3bdf918c)",Ben Bitdiddle,[email protected]

Then you can add in the operator overload functions for typeid.

Some users have reported issues with the above operator when using Rails and ActiveRecord – we recommend removing COMMUTATOR from the operator definition if you encounter issues.

Future work (contributions welcome)

  • Include examples not just for Postgres, but for other databases like MySQL as well.
  • Consider rewriting this library as a postgres extension. It would make it possible to use the standard typeid string representation without the need of extra functions.