Init Drizzle + D1

Set up Drizzle ORM with Cloudflare D1 database. Creates schema, migrations directory, and Drizzle config.

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Your Task

Follow these steps to add Drizzle ORM to an existing Cloudflare Workers project.

1. Check Prerequisites

Verify the project has:

• wrangler.jsonc with a D1 binding configured
• TypeScript configured (tsconfig.json)

If no D1 binding exists, inform user:

Run: npx wrangler d1 create <database-name>
Then add the binding to wrangler.jsonc

2. Install Dependencies

npm install drizzle-orm
npm install -D drizzle-kit better-sqlite3 @types/better-sqlite3

3. Create Directory Structure

src/
└── db/
    └── schema.ts
drizzle.config.ts
migrations/

4. Create Schema File

Create src/db/schema.ts:

import { sqliteTable, text, integer } from 'drizzle-orm/sqlite-core';

// Example users table - customize for your needs
export const users = sqliteTable('users', {
  id: integer('id').primaryKey({ autoIncrement: true }),
  email: text('email').notNull().unique(),
  name: text('name'),
  createdAt: integer('created_at', { mode: 'timestamp' }).$defaultFn(() => new Date()),
  updatedAt: integer('updated_at', { mode: 'timestamp' }).$defaultFn(() => new Date()),
});

// Add more tables as needed

5. Create Drizzle Config

Create drizzle.config.ts:

import { defineConfig } from 'drizzle-kit';

export default defineConfig({
  schema: './src/db/schema.ts',
  out: './migrations',
  dialect: 'sqlite',
  driver: 'd1-http',
  dbCredentials: {
    accountId: process.env.CLOUDFLARE_ACCOUNT_ID!,
    databaseId: process.env.CLOUDFLARE_DATABASE_ID!,
    token: process.env.CLOUDFLARE_D1_TOKEN!,
  },
});

6. Update wrangler.jsonc

Ensure D1 binding and migrations directory are configured:

{
  "d1_databases": [{
    "binding": "DB",
    "database_name": "<database-name>",
    "database_id": "<your-database-id>",
    "migrations_dir": "./migrations"
  }]
}

7. Create Database Helper

Create src/db/index.ts:

import { drizzle } from 'drizzle-orm/d1';
import * as schema from './schema';

export function createDb(d1: D1Database) {
  return drizzle(d1, { schema });
}

export type Database = ReturnType<typeof createDb>;
export * from './schema';

8. Add Scripts to package.json

{
  "scripts": {
    "db:generate": "drizzle-kit generate",
    "db:migrate:local": "wrangler d1 migrations apply <database-name> --local",
    "db:migrate:remote": "wrangler d1 migrations apply <database-name> --remote",
    "db:studio": "drizzle-kit studio"
  }
}

9. Generate Initial Migration

npm run db:generate

10. Provide Next Steps

✅ Drizzle ORM configured for D1!

📁 Structure:
   - src/db/schema.ts    (Define your tables)
   - src/db/index.ts     (Database helper)
   - drizzle.config.ts   (Drizzle Kit config)
   - migrations/         (SQL migrations)

🚀 Next steps:
   1. Edit src/db/schema.ts to define your tables
   2. npm run db:generate     (Generate migrations)
   3. npm run db:migrate:local (Apply to local)
   4. npm run db:migrate:remote (Apply to production)

💡 Usage in Worker:
   import { createDb } from './db';
   const db = createDb(env.DB);
   const users = await db.select().from(schema.users);

📚 Skill loaded: drizzle-orm-d1
   - 12 common issues auto-prevented
   - Use db.batch([]) for transactions (D1 doesn't support BEGIN)

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Critical Patterns Applied

1. Timestamp mode: Uses mode: 'timestamp' with $defaultFn() for dates
2. Batch API: D1 doesn't support SQL transactions - use db.batch([])
3. Migrations directory: Points to ./migrations in wrangler.jsonc
4. Local-first: Always test migrations locally before remote