Seeding a Database

In this post I am going to walk you through the process of setting up a development environment and seeding a database

First start off by initializing a new Next.js project

npx create-next-app@latest

Here you can see the settings I chose

Now Create a Postgres Database with Docker

docker run --rm --publish 5432:5432 -e POSTGRES_HOST_AUTH_METHOD=trust -e POSTGRES_DB=name postgres

Install the packages for prisma

npm i -D prisma
npm i @prisma/client

Initialize Prisma in the app

npx prisma init

Now modify the .env file

DATABASE_URL="postgresql://postgres@localhost:5432/name?schema=public"

We need to setup a basic prisma schema by adding a user [File: prisma.schema]

model user {
    id Int @id @default(autoincrement())
    email String @unique
    password String
    name String?
}

Create your first prisma migration

npx prisma migrate dev --name init

We now want to edit the package.json file so that when building, you generate a new prisma instance

...
"scripts": {
    ...
    "build": "prisma generate && next build",
},
...

We need to install a dev dependency that allows us to run scripts in typescript

npm i -D ts-node

Back to the package.json to add a script

...
"prisma": {
    "seed": "ts-node --compiler-options {\"module\":\"CommonJS\"} prisma/seed.ts",
},
"dependencies": {
    ...
},
...

In the prisma folder, create a seed.ts file

prisma/seed.ts

import { PrismaClient } from '@prisma/client'

const prisma = new PrismaClient()

async function main() {
	const user = await prisma.user.upsert({
		where: { email: 'test@test.com' },
		update: {},
		create: {
			email: 'test@test.com',
			name: 'Test User',
			password: `password`
		},
	})
	console.log({ user })
}

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

Now we can seed the database by running

npx prisma db seed

Set up the global prisma client

lib/prisma.ts

import { PrismaClient } from '@prisma/client'

const globalForPrisma = global as unknown as { prisma: PrismaClient }

export const prisma = globalForPrisma.prisma || new PrismaClient({ log: ['query'] })

if (process.env.NODE_ENV !== 'production') globalForPrisma.prisma

Now you can either use your own ORM that you may use or you can run the following command to see your user you created during the seed.

npx prisma studio