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Set up and use a Prisma Postgres database

Last reviewed: 4 months ago

Prisma Postgres ↗ is a managed, serverless PostgreSQL database. It supports features like connection pooling, caching, real-time subscriptions, and query optimization recommendations.

In this tutorial, you will learn how to:

  • Set up a Cloudflare Workers project with Prisma ORM ↗.
  • Create a Prisma Postgres instance from the Prisma CLI.
  • Model data and run migrations with Prisma Postgres.
  • Query the database from Workers.
  • Deploy the Worker to Cloudflare.

Prerequisites

To follow this guide, ensure you have the following:

  • Node.js v18.18 or higher installed.
  • An active Cloudflare account ↗.
  • A basic familiarity with installing and using command-line interface (CLI) applications.

1. Create a new Worker project

Begin by using C3 to create a Worker project in the command line:

Terminal window
npm create cloudflare@latest prisma-postgres-worker -- --type=hello-world --ts=true --git=true --deploy=false

Then navigate into your project:

Terminal window
cd ./prisma-postgres-worker

Your initial src/index.ts file currently contains a simple request handler:

src/index.ts
export default {
  async fetch(request, env, ctx): Promise<Response> {
    return new Response("Hello World!");
  },
} satisfies ExportedHandler<Env>;

2. Setup Prisma in your project

In this step, you will set up Prisma ORM with a Prisma Postgres database using the CLI. Then you will create and execute helper scripts to create tables in the database and generate a Prisma client to query it.

2.1. Install required dependencies

Install Prisma CLI as a dev dependency:

Terminal window
npm i -D prisma

Install the Prisma Accelerate client extension ↗ as it is required for Prisma Postgres:

Terminal window
npm i @prisma/extension-accelerate

Install the dotenv-cli package ↗ to load environment variables from .dev.vars:

Terminal window
npm i -D dotenv-cli

2.2. Create a Prisma Postgres database and initialize Prisma

Initialize Prisma in your application:

Terminal window
npx prisma@latest init --db

If you do not have a Prisma Data Platform ↗ account yet, or if you are not logged in, the command will prompt you to log in using one of the available authentication providers. A browser window will open so you can log in or create an account. Return to the CLI after you have completed this step.

Once logged in (or if you were already logged in), the CLI will prompt you to select a project name and a database region.

Once the command has terminated, it will have created:

  • A project in your Platform Console ↗ containing a Prisma Postgres database instance.
  • A prisma folder containing schema.prisma, where you will define your database schema.
  • An .env file in the project root, which will contain the Prisma Postgres database url DATABASE_URL=<your-prisma-postgres-database-url>.

Note that Cloudflare Workers do not support .env files. You will use a file called .dev.vars instead of the .env file that was just created.

2.3. Prepare environment variables

Rename the .env file in the root of your application to .dev.vars file:

Terminal window
mv .env .dev.vars

2.4. Apply database schema changes

Open the schema.prisma file in the prisma folder and add the following User model to your database:

prisma/schema.prisma
generator client {
  provider = "prisma-client-js"
}


datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}


model User {
  id  Int @id @default(autoincrement())
  email String
  name   String
}

Next, add the following helper scripts to the scripts section of your package.json:

package.json
"scripts": {
  "migrate": "dotenv -e .dev.vars -- npx prisma migrate dev",
  "generate": "dotenv -e .dev.vars -- npx prisma generate --no-engine",
  "studio": "dotenv -e .dev.vars -- npx prisma studio",
  // Additional worker scripts...
}

Run the migration script to apply changes to the database:

Terminal window
npm run migrate

When prompted, provide a name for the migration (for example, init).

After these steps are complete, Prisma ORM is fully set up and connected to your Prisma Postgres database.

3. Develop the application

Modify the src/index.ts file and replace its contents with the following code:

src/index.ts
import { PrismaClient } from "@prisma/client/edge";
import { withAccelerate } from "@prisma/extension-accelerate";


export interface Env {
  DATABASE_URL: string;
}


export default {
  async fetch(request, env, ctx): Promise<Response> {
    const path = new URL(request.url).pathname;
    if (path === "/favicon.ico")
      return new Response("Resource not found", {
        status: 404,
        headers: {
          "Content-Type": "text/plain",
        },
      });


    const prisma = new PrismaClient({
      datasourceUrl: env.DATABASE_URL,
    }).$extends(withAccelerate());


    const user = await prisma.user.create({
      data: {
        email: `Jon${Math.ceil(Math.random() * 1000)}@gmail.com`,
        name: "Jon Doe",
      },
    });


    const userCount = await prisma.user.count();


    return new Response(`\
Created new user: ${user.name} (${user.email}).
Number of users in the database: ${userCount}.
    `);
  },
} satisfies ExportedHandler<Env>;

Run the development server:

Terminal window
npm run dev

Visit https://localhost:8787 ↗ to see your app display the following output:

Terminal window
Number of users in the database: 1

Every time you refresh the page, a new user is created. The number displayed will increment by 1 with each refresh as it returns the total number of users in your database.

4. Deploy the application to Cloudflare

When the application is deployed to Cloudflare, it needs access to the DATABASE_URL environment variable that is defined locally in .dev.vars. You can use the npx wrangler secret put command to upload the DATABASE_URL to the deployment environment:

Terminal window
npx wrangler secret put DATABASE_URL

When prompted, paste the DATABASE_URL value (from .dev.vars). If you are logged in via the Wrangler CLI, you will see a prompt asking if you'd like to create a new Worker. Confirm by choosing "yes":

Terminal window
✔ There doesn't seem to be a Worker called "prisma-postgres-worker". Do you want to create a new Worker with that name and add secrets to it? … yes

Then execute the following command to deploy your project to Cloudflare Workers:

Terminal window
npm run deploy

The wrangler CLI will bundle and upload your application.

If you are not already logged in, the wrangler CLI will open a browser window prompting you to log in to the Cloudflare dashboard ↗.

Once the deployment completes, verify the deployment by visiting the live URL provided in the deployment output, such as https://{PROJECT_NAME}.workers.dev. If you encounter any issues, ensure the secrets were added correctly and check the deployment logs for errors.

Next steps

Congratulations on building and deploying a simple application with Prisma Postgres and Cloudflare Workers!

To enhance your application further:

To see how to build a real-time application with Cloudflare Workers and Prisma Postgres, read this ↗ guide.