Introducing SQG

Dec 17, 2024

SQG Team

We’re excited to announce SQG (SQL Query Generator), a tool that generates type-safe database access code from your SQL queries.

The Problem

Writing database code means maintaining SQL queries and matching TypeScript/Java types. When schemas change, you update both—and hope nothing breaks. ORMs abstract SQL away, but what if you want to write SQL directly while keeping type safety?

The Solution

SQG reads annotated .sql files, executes queries against real databases to introspect column types, and generates fully-typed wrapper code.

Write your SQL with simple annotations:

-- MIGRATE createUsersTable
CREATE TABLE users (id INTEGER PRIMARY KEY,
                    name TEXT NOT NULL,
                    email TEXT);

-- QUERY getUserById :one
@set id = 1
SELECT id, name, email FROM users WHERE id = ${id};

-- QUERY getUsers
SELECT id, name, email FROM users;

-- EXEC insertUser
@set name = 'John'
@set email = '[email protected]'
INSERT INTO users (name, email) VALUES (${name}, ${email});

SQG generates type-safe code:

export class Queries {
  getUserById(id: number): { id: number; name: string; email: string | null } | undefined
  getUsers(): { id: number; name: string; email: string | null }[]
  insertUser(name: string, email: string): RunResult
}

Key Features

• Type-safe by design - Column types inferred from your actual database
• Multiple databases - SQLite, DuckDB, and PostgreSQL
• Multiple languages - Generate TypeScript or Java from the same SQL
• DBeaver compatible - Develop queries in DBeaver, generate code from the same file
• Zero runtime overhead - Generated code is plain function calls

Get Started

Install SQG:

pnpm add -g @sqg/sqg
pnpm approve-builds -g  # needed for sqlite dependency

Create a sqg.yaml config and your SQL file, then run sqg sqg.yaml. Check out the Getting Started guide for details.

We’d love your feedback! File issues and feature requests on GitHub.