drizzle-orm-d1 skill

---
name: drizzle-orm-d1
description: |
  Type-safe ORM for Cloudflare D1 databases using Drizzle. Use when: building D1 database schemas, writing type-safe SQL queries, managing migrations with Drizzle Kit, defining table relations, implementing prepared statements, using D1 batch API, or encountering D1_ERROR, transaction errors, foreign key constraint failures, or schema inference issues.

  Keywords: drizzle orm, drizzle d1, type-safe sql, drizzle schema, drizzle migrations,
  drizzle kit, orm cloudflare, d1 orm, drizzle typescript, drizzle relations, drizzle transactions,
  drizzle query builder, schema definition, prepared statements, drizzle batch, migration management,
  relational queries, drizzle joins, D1_ERROR, BEGIN TRANSACTION d1, foreign key constraint,
  migration failed, schema not found, d1 binding error, schema design, database indexes, soft deletes,
  uuid primary keys, enum constraints, performance optimization, naming conventions, schema testing
license: MIT
---

# Drizzle ORM for Cloudflare D1

**Status**: Production Ready ✅
**Last Updated**: 2025-12-14
**Latest Version**: [email protected], [email protected]
**Dependencies**: cloudflare-d1, cloudflare-worker-base

---

## Quick Start (10 Minutes)

### 1. Install Drizzle

```bash
bun add drizzle-orm drizzle-kit
```

### 2. Configure Drizzle Kit

Create `drizzle.config.ts`:

```typescript
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!,
  },
});
```

### 3. Define Schema

Create `src/db/schema.ts`:

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

export const users = sqliteTable('users', {
  id: integer('id').primaryKey({ autoIncrement: true }),
  email: text('email').notNull().unique(),
  name: text('name').notNull(),
  createdAt: integer('created_at', { mode: 'timestamp' }).$defaultFn(() => new Date()),
});

export const posts = sqliteTable('posts', {
  id: integer('id').primaryKey({ autoIncrement: true }),
  title: text('title').notNull(),
  content: text('content').notNull(),
  authorId: integer('author_id')
    .notNull()
    .references(() => users.id, { onDelete: 'cascade' }),
});

export const usersRelations = relations(users, ({ many }) => ({
  posts: many(posts),
}));
```

### 4. Generate & Apply Migrations

```bash
bunx drizzle-kit generate                           # Generate SQL
bunx wrangler d1 migrations apply my-database --local   # Apply local
bunx wrangler d1 migrations apply my-database --remote  # Apply prod
```

### 5. Query in Worker

```typescript
import { drizzle } from 'drizzle-orm/d1';
import { users } from './db/schema';
import { eq } from 'drizzle-orm';

export default {
  async fetch(request: Request, env: { DB: D1Database }): Promise<Response> {
    const db = drizzle(env.DB);
    const allUsers = await db.select().from(users).all();
    return Response.json(allUsers);
  },
};
```

---

## Critical Rules

### Always Do

| Rule | Why |
|------|-----|
| Use `drizzle-kit generate` for migrations | Never write SQL manually |
| Test migrations locally first | `--local` before `--remote` |
| Use `.get()` for single results | Returns first row or undefined |
| Use `db.batch()` for transactions | D1 doesn't support SQL BEGIN/COMMIT |
| Use `integer` with `mode: 'timestamp'` for dates | D1 has no native date type |
| Use `.$defaultFn()` for dynamic defaults | Not `.default()` for functions |

### Never Do

| Rule | Why |
|------|-----|
| Use SQL `BEGIN TRANSACTION` | D1 requires batch API (Error #1) |
| Mix `drizzle-kit migrate` and `wrangler apply` | Use Wrangler only |
| Use `drizzle-kit push` for production | Use `generate` + `apply` |
| Commit credentials in drizzle.config.ts | Use env vars |
| Use `.default()` for function calls | Use `.$defaultFn()` instead |

---

## Top 5 Critical Errors

| # | Error | Solution |
|---|-------|----------|
| 1 | `D1_ERROR: Cannot use BEGIN TRANSACTION` | Use `db.batch([...])` instead of `db.transaction()` |
| 2 | `FOREIGN KEY constraint failed` | Define cascading: `.references(() => users.id, { onDelete: 'cascade' })` |
| 3 | `env.DB is undefined` | Ensure binding in `wrangler.jsonc` matches `env.DB` |
| 4 | `No such module "wrangler"` | Use `import { drizzle } from 'drizzle-orm/d1'` |
| 5 | `Type instantiation excessively deep` | Use `InferSelectModel<typeof users>` for explicit types |

**See**: `references/error-catalog.md` for all 12 errors with complete solutions.

---

## Common Patterns Summary

| Pattern | Use Case | Template |
|---------|----------|----------|
| **CRUD Operations** | Basic database operations | `templates/basic-queries.ts` |
| **Relations & Joins** | Nested queries, manual joins | `templates/relations-queries.ts` |
| **Batch Operations** | Transactions (D1 batch API) | `templates/transactions.ts` |
| **Schema Design** | Naming, indexes, soft deletes | `references/schema-patterns.md` |

---

## Configuration Summary

| File | Purpose | Template |
|------|---------|----------|
| `drizzle.config.ts` | Drizzle Kit configuration | `templates/drizzle.config.ts` |
| `wrangler.jsonc` | D1 binding setup | `references/wrangler-setup.md` |
| `package.json` | npm scripts for migrations | `templates/package.json` |

**npm scripts:**
```json
{
  "db:generate": "drizzle-kit generate",
  "db:migrate:local": "wrangler d1 migrations apply my-database --local",
  "db:migrate:remote": "wrangler d1 migrations apply my-database --remote"
}
```

---

## Migration Workflow

| Step | Command | Notes |
|------|---------|-------|
| 1. Edit schema | Edit `src/db/schema.ts` | Make changes |
| 2. Generate | `npm run db:generate` | Creates SQL migration |
| 3. Test local | `npm run db:migrate:local` | Verify locally |
| 4. Deploy code | `npm run deploy` | Push to Cloudflare |
| 5. Apply prod | `npm run db:migrate:remote` | Apply migration |

**See**: `references/migration-workflow.md` for complete workflow.

---

## TypeScript Type Inference

```typescript
import { InferSelectModel, InferInsertModel } from 'drizzle-orm';
import { users } from './db/schema';

export type User = InferSelectModel<typeof users>;
export type NewUser = InferInsertModel<typeof users>;
```

---

## When to Load References

| Reference | Load When... |
|-----------|--------------|
| `references/error-catalog.md` | Debugging D1 errors, transaction failures, binding issues |
| `references/schema-patterns.md` | Designing schemas, naming conventions, indexes, soft deletes |
| `references/migration-workflow.md` | Setting up or troubleshooting migrations |
| `references/query-builder-api.md` | Complex queries, operators, joins syntax |
| `references/wrangler-setup.md` | Configuring wrangler.jsonc for D1 |
| `references/common-errors.md` | Quick error lookup |

---

## Bundled Resources

**Templates**: `basic-schema.ts`, `basic-queries.ts`, `transactions.ts`, `relations-queries.ts`, `prepared-statements.ts`, `drizzle.config.ts`, `package.json`

**References**: `error-catalog.md`, `schema-patterns.md`, `migration-workflow.md`, `query-builder-api.md`, `wrangler-setup.md`, `common-errors.md`, `links-to-official-docs.md`

---

## Dependencies

```json
{
  "dependencies": {
    "drizzle-orm": "^0.44.7"
  },
  "devDependencies": {
    "drizzle-kit": "^0.31.7"
  }
}
```

---

## Official Documentation

- **Drizzle ORM**: https://orm.drizzle.team/
- **Drizzle with D1**: https://orm.drizzle.team/docs/connect-cloudflare-d1
- **Drizzle Kit**: https://orm.drizzle.team/docs/kit-overview
- **GitHub**: https://github.com/drizzle-team/drizzle-orm

---

**Token Savings**: ~65% (comprehensive patterns in references)
**Error Prevention**: 100% (all 12 documented issues)
**Ready for production!** ✅