prisma-d1

name	prisma-d1
description	Prisma ORM with Cloudflare D1 — schema configuration, migration workflow, client setup, and deployment. Load when working with Prisma + D1 migrations, schema changes, or PrismaClient instantiation in Workers.

Prisma ORM + Cloudflare D1

Setup, migration, and deployment guide for Prisma with Cloudflare D1.

Retrieval Source

Source	URL	Use for
Prisma D1 Guide	https://www.prisma.io/docs/guides/deployment/cloudflare-d1	Official guide
Prisma Migrate Diff	https://www.prisma.io/docs/orm/reference/prisma-cli-reference#migrate-diff	migrate diff options
D1 Docs	https://developers.cloudflare.com/d1	D1 specs and limitations

Required Packages

bun add prisma --dev
bun add @prisma/client @prisma/adapter-d1

Schema Configuration (prisma/schema.prisma)

generator client {
  provider = "prisma-client"
  output   = "../src/generated/prisma"
  runtime  = "cloudflare"
}

datasource db {
  provider = "sqlite"
}

Key points:

• provider = "sqlite" — D1 is SQLite-based
• runtime = "cloudflare" — generates client for Cloudflare Workers runtime
• output — must be explicitly specified

Migration Workflow

D1 does not use standard prisma migrate dev. Instead, use prisma migrate diff to generate SQL, then wrangler d1 execute to apply it.

Initial Migration

# Generate SQL (empty state -> current schema)
bunx prisma migrate diff \
  --from-empty \
  --to-schema prisma/schema.prisma \
  --script > migrations/0001_init.sql

# Apply to local D1
bunx wrangler d1 execute <DB_NAME> --local \
  --file="./migrations/0001_init.sql"

# Apply to remote D1
bunx wrangler d1 execute <DB_NAME> --remote \
  --file="./migrations/0001_init.sql"

Subsequent Migrations

# Generate SQL (current local D1 state -> current schema)
bunx prisma migrate diff \
  --from-local-d1 \
  --to-schema prisma/schema.prisma \
  --script > migrations/0002_<description>.sql

# Apply locally
bunx wrangler d1 execute <DB_NAME> --local \
  --file="./migrations/0002_<description>.sql"

# Apply remotely
bunx wrangler d1 execute <DB_NAME> --remote \
  --file="./migrations/0002_<description>.sql"

Migration Naming Convention

Place sequentially numbered SQL files in the migrations/ directory:

• 0001_init.sql
• 0002_add_exercises.sql
• 0003_add_index.sql

Prisma Client Generation

bunx prisma generate

Must be run after every schema change. Generates typed client at the output path.

Using PrismaClient in Workers

import { PrismaClient } from '@/generated/prisma/client'
import { PrismaD1 } from '@prisma/adapter-d1'

// Inside Workers fetch handler:
const adapter = new PrismaD1(env.DB)
const prisma = new PrismaClient({ adapter })

const users = await prisma.user.findMany()

// Resource cleanup (required)
ctx.waitUntil(prisma.$disconnect())

Important:

• env.DB must match the binding name in wrangler.toml / wrangler.jsonc d1_databases
• Always call prisma.$disconnect() — prevents memory leaks
• Use ctx.waitUntil() to disconnect asynchronously after response is sent

wrangler.toml D1 Binding Configuration

[[d1_databases]]
binding = "DB"
database_name = "your-db-name"
database_id = "your-db-id"

prisma.config.ts (for migrations)

import 'dotenv/config'
import { defineConfig, env } from 'prisma/config'

export default defineConfig({
  schema: 'prisma/schema.prisma',
  migrations: {
    path: 'prisma/migrations'
  },
  datasource: {
    url: env('DATABASE_URL')
  }
})

.env:

DATABASE_URL="file:./prisma/db.sqlite"

Common Pitfalls

1. prisma migrate dev does not work — D1 requires migrate diff + wrangler d1 execute workflow
2. Forgetting prisma generate — client must be regenerated after schema changes
3. Binding name mismatch — binding in wrangler.toml must match env.DB in code
4. Missing $disconnect() — causes Workers memory exhaustion
5. Local and remote are separate — migrations must be applied independently with --local and --remote
6. SQLite limitations — D1 is SQLite-based, so some Prisma features like @db.Text and Json type are unavailable