PostgreSQL

PostgreSQL is an open-source relational database. In this guide, you will learn how to set up a new TypeScript project from scratch, connect it to PostgreSQL using Prisma ORM, and generate a Prisma Client for type-safe access to your database.

You also need:

• A PostgreSQL database server running and accessible
• Database connection details (host, port, username, password, database name)

mkdir hello-prisma

cd hello-prisma

Initialize a TypeScript project:

bun init

bun add typescript tsx @types/node --dev

bunx tsc --init

pnpm init
pnpm add typescript tsx @types/node --save-dev
pnpm tsc --init

yarn init
yarn add typescript tsx @types/node --dev
yarn tsc --init

npm init
npm install typescript tsx @types/node --save-dev
npx tsc --init

Install the packages needed for this quickstart:

bun add prisma@prev @types/pg --dev

bun add @prisma/client@7 @prisma/adapter-pg pg dotenv

pnpm add prisma@prev @types/pg --save-dev
pnpm add @prisma/client@7 @prisma/adapter-pg pg dotenv

yarn add prisma@prev @types/pg --dev
yarn add @prisma/client@7 @prisma/adapter-pg pg dotenv

npm install prisma@prev @types/pg --save-dev
npm install @prisma/client@7 @prisma/adapter-pg pg dotenv

Here's what each package does:

• prisma - The Prisma CLI for running commands like prisma init, prisma migrate, and prisma generate
• @prisma/client - The Prisma Client library for querying your database
• @prisma/adapter-pg - The node-postgres driver adapter that connects Prisma Client to your database
• pg - The node-postgres database driver
• @types/pg - TypeScript type definitions for node-postgres
• dotenv - Loads environment variables from your .env file

Update tsconfig.json for ESM compatibility:

{

  "compilerOptions": {

    "module": "ESNext",

    "moduleResolution": "bundler",

    "target": "ES2023",

    "strict": true,

    "esModuleInterop": true,

    "ignoreDeprecations": "6.0"

  }

}

Update package.json to enable ESM:

{

  "type": "module"

}

You can now run Prisma CLI commands using your package manager:

bunx prisma

pnpm prisma

yarn prisma

npx prisma

Next, set up your Prisma ORM project by creating your Prisma Schema file with the following command:

bunx --bun prisma init --datasource-provider postgresql --output ../generated/prisma

pnpm prisma init --datasource-provider postgresql --output ../generated/prisma

yarn prisma init --datasource-provider postgresql --output ../generated/prisma

npx prisma init --datasource-provider postgresql --output ../generated/prisma

This command does a few things:

• Creates a prisma/ directory with a schema.prisma file containing your database connection and schema models
• Creates a .env file in the root directory for environment variables
• Creates a prisma7.config.ts file for Prisma configuration

The generated prisma7.config.ts file looks like this:

// This file was generated by Prisma, and assumes you have installed the following:

// npm install --save-dev prisma dotenv

import "dotenv/config";

import { defineConfig } from "prisma/config";

export default defineConfig({

  schema: "prisma/schema.prisma",

  migrations: {

    path: "prisma/migrations",

  },

  datasource: {

    url: process.env["DATABASE_URL"],

  },

});

The generated schema uses the ESM-first prisma-client generator with a custom output path:

generator client {

  provider = "prisma-client"

  output   = "../generated/prisma"

}

datasource db {

  provider = "postgresql"

}

Update your .env file with your PostgreSQL connection string:

DATABASE_URL="postgresql://username:password@localhost:5432/mydb?schema=public"

Replace the placeholders with your actual database credentials:

• username: Your PostgreSQL username
• password: Your PostgreSQL password
• localhost:5432: Your PostgreSQL host and port
• mydb: Your database name

Open prisma/schema.prisma and add the following models:

generator client {

  provider = "prisma-client"

  output   = "../generated/prisma"

}

datasource db {

  provider = "postgresql"

}

model User { 

  id    Int     @id @default(autoincrement()) 

  email String  @unique

  name  String?

  posts Post[]

} 

model Post { 

  id        Int     @id @default(autoincrement()) 

  title     String

  content   String?

  published Boolean @default(false) 

  author    User    @relation(fields: [authorId], references: [id]) 

  authorId  Int

} 

Create your first migration to set up the database tables:

bunx prisma migrate dev --name init

pnpm prisma migrate dev --name init

yarn prisma migrate dev --name init

npx prisma migrate dev --name init

This command creates the database tables based on your schema.

Now run the following command to generate the Prisma Client:

bunx prisma generate

pnpm prisma generate

yarn prisma generate

npx prisma generate

Now that you have all the dependencies installed, you can instantiate Prisma Client. You need to pass an instance of the Prisma ORM driver adapter to the PrismaClient constructor:

import "dotenv/config";

import { PrismaPg } from "@prisma/adapter-pg";

import { PrismaClient } from "../generated/prisma/client";

const connectionString = `${process.env.DATABASE_URL}`;

const adapter = new PrismaPg({ connectionString });

const prisma = new PrismaClient({ adapter });

export { prisma };

Create a script.ts file to test your setup:

import { prisma } from "./lib/prisma";

async function main() {

  // Create a new user with a post

  const user = await prisma.user.create({

    data: {

      name: "Alice",

      email: "alice@prisma.io",

      posts: {

        create: {

          title: "Hello World",

          content: "This is my first post!",

          published: true,

        },

      },

    },

    include: {

      posts: true,

    },

  });

  console.log("Created user:", user);

  // Fetch all users with their posts

  const allUsers = await prisma.user.findMany({

    include: {

      posts: true,

    },

  });

  console.log("All users:", JSON.stringify(allUsers, null, 2));

}

main()

  .then(async () => {

    await prisma.$disconnect();

  })

  .catch(async (e) => {

    console.error(e);

    await prisma.$disconnect();

    process.exit(1);

  });

Run the script:

bunx tsx script.ts

pnpm dlx tsx script.ts

yarn dlx tsx script.ts

npx tsx script.ts

You should see the created user and all users printed to the console.

Prisma Studio is a visual editor for your database. Launch it with:

npx prisma studio

Prisma ORM is set up. These are the pages you are most likely to need next:

• Learn more about Prisma Client: Explore the Prisma Client API for advanced querying, filtering, and relations
• Database migrations: Learn about Prisma Migrate for evolving your database schema
• Performance optimization: Discover query optimization techniques
• Build a full application: Check out our framework guides to integrate Prisma ORM with Next.js, Express, and more
• Join the community: Connect with other developers on Discord

• PostgreSQL database connector
• Prisma Config reference
• Database connection management