prisma db seed

Runs your database seed script to populate data.

Command

prisma db seed [options]

What It Does

• Executes your configured seed script
• Populates database with initial/test data
• Runs independently (not auto-run by migrations in v7)

Options

Configuration

Configure seed script in prisma.config.ts:

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

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

Common seed commands

// TypeScript with tsx
seed: 'tsx prisma/seed.ts'

// TypeScript with ts-node
seed: 'ts-node prisma/seed.ts'

// JavaScript
seed: 'node prisma/seed.js'

Seed Script Example

// prisma/seed.ts
import { PrismaClient } from '../generated/client'

const prisma = new PrismaClient()

async function main() {
  // Create users
  const alice = await prisma.user.upsert({
    where: { email: '[email protected]' },
    update: {},
    create: {
      email: '[email protected]',
      name: 'Alice',
      posts: {
        create: {
          title: 'Hello World',
          published: true,
        },
      },
    },
  })

  const bob = await prisma.user.upsert({
    where: { email: '[email protected]' },
    update: {},
    create: {
      email: '[email protected]',
      name: 'Bob',
    },
  })

  console.log({ alice, bob })
}

main()
  .then(async () => {
    await prisma.$disconnect()
  })
  .catch(async (e) => {
    console.error(e)
    await prisma.$disconnect()
    process.exit(1)
  })

Examples

Run seed

prisma db seed

With custom arguments

prisma db seed -- --environment development

Arguments after -- are passed to your seed script.

v7 Changes

In Prisma 7, seeding is NOT automatic after migrations:

# v7 workflow
prisma migrate dev --name init
prisma generate
prisma db seed  # Must run explicitly

Previously (v6), migrate dev and migrate reset auto-ran seeds.

Idempotent Seeding

Use upsert to make seeds re-runnable:

// Good: Can run multiple times
await prisma.user.upsert({
  where: { email: '[email protected]' },
  update: {},  // Don't change existing
  create: { email: '[email protected]', name: 'Alice' },
})

// Bad: Fails on second run
await prisma.user.create({
  data: { email: '[email protected]', name: 'Alice' },
})

Common Patterns

Development reset

prisma migrate reset --force
prisma db seed

Conditional seeding

// prisma/seed.ts
const count = await prisma.user.count()
if (count === 0) {
  // Only seed if empty
  await seedUsers()
}

Environment-specific seeds

// prisma/seed.ts
const env = process.env.NODE_ENV || 'development'

if (env === 'development') {
  await seedDevData()
} else if (env === 'test') {
  await seedTestData()
}

Best Practices

1. Use upsert for idempotent seeds
2. Keep seeds focused and minimal
3. Use realistic but fake data
4. Document required seed data
5. Version control your seed scripts