Type-safe schema generator, part IV

Well, it's good enough for my current needs.

I can generate typed CRUD operations for the style of queries that I'm writing.

Supports SELECT, UPDATE, INSERT, and DELETE, with JOINs (automatically makes fields nullable for OUTER JOINs). Aliased columns, COUNT, SELECT * ... and RETURNING.

Uses nominal types for primary and foreign keys.

For the following query

INSERT INTO
  users AS u (
    telegram_id,
    first_name,
    last_name,
    username,
    photo_url
  )
VALUES
  (
    $telegram_id,
    $first_name,
    $last_name,
    $username,
    $photo_url
  )
ON CONFLICT(telegram_id) DO
UPDATE
  SET
    first_name = excluded.first_name,
    last_name = excluded.last_name,
    username = excluded.username,
    photo_url = excluded.photo_url
RETURNING *;

Output looks roughly like this

import type { Brand } from "../../brand.ts";
import Database from "bun:sqlite";

// This file is automatically generated and should not be edited by hand
type MakeBunHappy = Record<string, never>;
export type UserUserId = Brand<number, 'user:user_id'>;

export interface UpsertUserInput {
    readonly $telegram_id: number;
    readonly $first_name: string;
    readonly $last_name: string;
    readonly $username: string;
    readonly $photo_url: string;
}

export interface UpsertUserOutput {
    readonly user_id: UserUserId;
    readonly telegram_id: number;
    readonly first_name: string;
    readonly last_name: string;
    readonly username: string;
    readonly photo_url: string;
    readonly approved: number;
}

export function getUpsertUserQuery(connection: Database) {
    return connection.query<UpsertUserOutput, UpsertUserInput & MakeBunHappy>(`... query text here ...`);
}

❯ cloc .
      11 text files.
      11 unique files.
       0 files ignored.

github.com/AlDanial/cloc v 1.90  T=0.02 s (603.6 files/s, 44449.2 lines/s)
-------------------------------------------------------------------------------
Language                     files          blank        comment           code
-------------------------------------------------------------------------------
TypeScript                      11             79              4            727
-------------------------------------------------------------------

Not too bad...

It's too crusty to be published – but if you're interested drop me a line.

#schema #typesafe