Database

Migrations

Database migration workflow with Drizzle Kit — generate, run, roll back, and manage schema changes.

Migrations

OmniSvelte uses Drizzle Kit for migrations. The generated src/lib/db/server/schema.ts is the source of truth — Drizzle Kit diffs it against your database to produce migration SQL.

Setup

OmniSvelte writes a drizzle.config.ts on first run:

// drizzle.config.ts (auto-generated — safe to edit)
import { defineConfig } from 'drizzle-kit';
 
export default defineConfig({
  schema:  './src/lib/db/server/schema.ts',
  out:     './drizzle/migrations',
  dialect: 'postgresql',
  dbCredentials: { url: process.env.DATABASE_URL! }
});

Add convenience scripts to package.json:

json

{
  "scripts": {
    "db:push":    "drizzle-kit push",
    "db:generate": "drizzle-kit generate",
    "db:migrate": "drizzle-kit migrate",
    "db:studio":  "drizzle-kit studio",
    "db:drop":    "drizzle-kit drop"
  }
}

Development workflow

During development, use db:push — it applies schema changes directly without creating migration files:

bash

pnpm db:push

Safe for local dev. Never use db:push in production.

Production workflow

Generate a migration file from your schema changes:

bash

pnpm db:generate --name add_published_to_posts

This creates drizzle/migrations/0001_add_published_to_posts.sql.

Commit the migration file.
Run pending migrations in CI/CD or on deploy:

bash

pnpm db:migrate

Drizzle Studio

Visual database browser — runs in your browser:

bash

pnpm db:studio
# Open https://local.drizzle.studio

Migration file structure

drizzle/
  migrations/
    0000_initial_schema.sql
    0001_add_published_to_posts.sql
    0002_add_tags_table.sql
    meta/
      _journal.json      ← migration history
      0000_snapshot.json ← schema snapshots for diffing

Rolling back

Drizzle Kit doesn't auto-generate rollbacks. Write a down migration manually or use db:drop to remove a specific migration from the journal:

bash

pnpm db:drop
# Interactive: select which migration to remove from the journal

Seeding

OmniSvelte doesn't ship a seeder runner yet (planned for v0.2). Use a plain script for now:

// scripts/seed.ts
import { db }   from '../src/lib/db/server/index.js';
import { users } from '../src/lib/db/server/schema.js';
 
await db.insert(users).values([
  { name: 'Admin', email: 'admin@example.com', role: 'admin' }
]);
console.log('Seeded!');
process.exit(0);

Run with:

bash

npx tsx scripts/seed.ts

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