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Seeding your database

This guide describes how to seed your database using Prisma Client and Prisma's integrated seeding functionality. Seeding allows you to consistently re-create the same data in your database and can be used to:

  • Populate your database with data that is required for your application to start - for example, a default language or a default currency.
  • Provide basic data for validating and using your application in a development environment. This is particularly useful if you are using Prisma Migrate, which sometimes requires resetting your development database.

How to seed your database in Prisma

Prisma's integrated seeding functionality expects a command in the "seed" key in the "prisma" key of your package.json file. This can be any command, prisma db seed will just execute it. In this guide and as a default, we recommend writing a seed script inside your project's prisma/ folder and starting it with the command.

TypeScript
JavaScript
"prisma": {
  "seed": "ts-node prisma/seed.ts"
},
With TypeScript,ts-node does transpiling and typechecking by default; typechecking can be disabled with the following flag --transpile-only.
Example: "seed": "ts-node --transpile-only prisma/seed.ts"
This can be useful to reduce memory usage (RAM) and increase execution speed of the seed script.

Integrated seeding with Prisma Migrate

Database seeding happens in two ways with Prisma: manually with prisma db seed and automatically in prisma migrate dev and prisma migrate reset.

With prisma db seed, you decide when to invoke the seed command. It can be useful for a test setup or to prepare a new development environment, for example.

Prisma Migrate also integrates seamlessly with your seeds, assuming you follow the steps in the section below. When Prisma Migrate resets the development database, seeding is triggered automatically if you have a "seed" property in the "prisma" section in your package.json.

Prisma Migrate resets the database and triggers seeding in the following scenarios:

  • You manually run the prisma migrate reset CLI command.
  • The database is reset interactively in the context of using prisma migrate dev - for example, as a result of migration history conflicts or database schema drift.
  • When you want to use prisma migrate dev or prisma migrate reset without seeding, you can pass the --skip-seed flag.

Example seed scripts

Here we suggest some specific seed scripts for different situations. You are free to customize these in any way, but can also use them as presented here:

Seeding your database with TypeScript or JavaScript

TypeScript
JavaScript

  1. Create a new file named seed.ts. This can be placed anywhere within your projects folder structure. The below example places it in the /prisma folder.

  2. In the seed.ts file, import Prisma Client, initialize it and create some records. As an example, take the following Prisma schema with a User and Post model:

    schema.prisma
    1model User {
    2  id    Int    @id @default(autoincrement())
    3  email String @unique
    4  name  String
    5  posts Post[]
    6}
    7

    8model Post {
    9  id        Int     @id @default(autoincrement())
    10  title     String
    11  content   String
    12  published Boolean
    13  user      User    @relation(fields: [userId], references: [id])
    14  userId    Int
    15}

    Create some new users and posts in your seed.ts file:

    seed.ts
    1import { PrismaClient } from '@prisma/client'
    2const prisma = new PrismaClient()
    3async function main() {
    4  const alice = await prisma.user.upsert({
    5    where: { email: 'alice@prisma.io' },
    6    update: {},
    7    create: {
    8      email: 'alice@prisma.io',
    9      name: 'Alice',
    10      posts: {
    11        create: {
    12          title: 'Check out Prisma with Next.js',
    13          content: 'https://www.prisma.io/nextjs',
    14          published: true,
    15        },
    16      },
    17    },
    18  })
    19  const bob = await prisma.user.upsert({
    20    where: { email: 'bob@prisma.io' },
    21    update: {},
    22    create: {
    23      email: 'bob@prisma.io',
    24      name: 'Bob',
    25      posts: {
    26        create: [
    27          {
    28            title: 'Follow Prisma on Twitter',
    29            content: 'https://twitter.com/prisma',
    30            published: true,
    31          },
    32          {
    33            title: 'Follow Nexus on Twitter',
    34            content: 'https://twitter.com/nexusgql',
    35            published: true,
    36          },
    37        ],
    38      },
    39    },
    40  })
    41  console.log({ alice, bob })
    42}
    43main()
    44  .then(async () => {
    45    await prisma.$disconnect()
    46  })
    47  .catch(async (e) => {
    48    console.error(e)
    49    await prisma.$disconnect()
    50    process.exit(1)
    51  })

  3. Add typescript, ts-node and @types/node development dependencies:

    npm install -D typescript ts-node @types/node

  1. Add the prisma.seed field to your package.json file:

    package.json
    1{
    2  "name": "my-project",
    3  "version": "1.0.0",
    4  "prisma": {
    5    "seed": "ts-node prisma/seed.ts"
    6  },
    7  "devDependencies": {
    8    "@types/node": "^14.14.21",
    9    "ts-node": "^9.1.1",
    10    "typescript": "^4.1.3"
    11  }
    12}

    Some projects may require you to add compile options. When using Next.js for example, you would setup your seed script like so:

    package.json
    1"prisma": {
    2  "seed": "ts-node --compiler-options {\"module\":\"CommonJS\"} prisma/seed.ts"
    3},

  2. To seed the database, run the db seed CLI command:

    npx prisma db seed

Seeding your database via any language (with a Bash script)

In addition to TypeScript and JavaScript, you can also use a Bash script (seed.sh) to seed your database in another language such as Go, or plain SQL.

Go
SQL

The following example runs a Go script in the same folder as seed.sh:

seed.sh
1#!/bin/sh
2# -e Exit immediately when a command returns a non-zero status.
3# -x Print commands before they are executed
4set -ex
5# Seeding command
6go run ./seed/

User-defined arguments

This feature is available from version 4.15.0 and later.

prisma db seed allows you to define custom arguments in your seed file that you can pass to the prisma db seed command. For example, you could define your own arguments to seed different data for different environments or partially seeding data in some tables.

Here is an example seed file that defines a custom argument to seed different data in different environments:

"seed.js"
1import { parseArgs } from 'node:util'
2

3const options = {
4  environment: { type: 'string' },
5}
6

7async function main() {
8  const {
9    values: { environment },
10  } = parseArgs({ options })
11

12  switch (environment) {
13    case 'development':
14      /** data for your development */
15      break
16    case 'test':
17      /** data for your test environment */
18      break
19    default:
20      break
21  }
22}
23

24main()
25  .then(async () => {
26    await prisma.$disconnect()
27  })
28  .catch(async (e) => {
29    console.error(e)
30    await prisma.$disconnect()
31    process.exit(1)
32  })

You can then provide the environment argument when using prisma db seed by adding a delimiter — -- —, followed by your custom arguments:

npx prisma db seed -- --environment development

Going further

Here's a non-exhaustive list of other tools you can integrate with Prisma in your development workflow to seed your database:

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