Introduction to Using Prisma ORM with NodeJS and ExpressJS

Introduction

Prisma is a next-generation ORM (Object-Relational Mapping) for NodeJS and TypeScript. It provides a powerful and flexible way to interact with your database and helps in building robust and scalable applications. In this article, we’ll walk through the steps to set up and use Prisma ORM with NodeJS and ExpressJS for a website.

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Here is what we are planning to implement

graph TD
    Start[User Submits Form] -->|POST /save| A[Express Route Handler]
    A -->|Extract form data| B[username & email]
    B -->|client.set | C[Postgres Database]
    C -->|Data stored| D[Success Redirect to Homepage]
    A -->|Error occurs| E[Handle Error and Send Error Message]
    
    StartView[User Requests Data] -->|GET /view/:username| F[Express Route Handler]
    F -->|Extract username param| G[username]
    G -->|client.get| C
    C -->|Data Retrieved| H[Render View with username & email]
    F -->|Error occurs| I[Handle Error and Send Error Message]
    
    style A fill:#FFC300,stroke:#333,stroke-width:2px,color:#000000
    style F fill:#FFC300,stroke:#333,stroke-width:2px,color:#000000
    style C fill:#66B2FF,stroke:#333,stroke-width:2px,color:#000000
    style D fill:#28A745,stroke:#333,stroke-width:2px,color:#000000
    style H fill:#28A745,stroke:#333,stroke-width:2px,color:#000000
    style E fill:#FF5733,stroke:#333,stroke-width:2px,color:#000000
    style I fill:#FF5733,stroke:#333,stroke-width:2px,color:#000000

Prerequisites

Before we begin, ensure you have the following installed:

• NodeJS
• npm (Node Package Manager)
• PostgreSQL (or other compatible databases like MySQL, SQLite, etc.)

Setting Up Your Project

1. Initialize a new NodeJS project:

mkdir prisma-express-app
cd prisma-express-app
npm init -y

1. Install dependencies:

npm install express prisma @prisma/client

1. Install the Prisma CLI:

npm install prisma -D
npx prisma init

Configuring Prisma

The npx prisma init command creates a prisma directory with a schema.prisma file. This is where you’ll define your data model and database connection.

1. Update your schema.prisma file to configure your database:

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

generator client {
  provider = "prisma-client-js"
}

1. Set up your database URL in the .env file:

DATABASE_URL="postgresql://username:password@localhost:5432/mydatabase"

1. Define your data model in schema.prisma:

model User {
  id        Int      @id @default(autoincrement())
  email     String   @unique
  name      String?
  createdAt DateTime @default(now())
}

Migrate Your Database

With your data model defined, it’s time to migrate your database.

npx prisma migrate dev --name init

This command will generate the necessary SQL and apply it to your database.

Using Prisma Client in Your ExpressJS App

1. Generate Prisma Client:

npx prisma generate

1. Create your ExpressJS server:

// index.js
const express = require('express');
const { PrismaClient } = require('@prisma/client');

const app = express();
const prisma = new PrismaClient();

app.use(express.json());

// Create a new user
app.post('/user', async (req, res) => {
  const { email, name } = req.body;
  try {
    const user = await prisma.user.create({
      data: {
        email,
        name,
      },
    });
    res.json(user);
  } catch (e) {
    res.status(400).json({ error: 'User creation failed' });
  }
});

// Get all users
app.get('/users', async (req, res) => {
  const users = await prisma.user.findMany();
  res.json(users);
});

// Start the server
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});

1. Run your server:

node index.js

Conclusion

In this article, we walked through the steps of setting up Prisma ORM with NodeJS and ExpressJS. We configured Prisma, defined a data model, migrated our database, and created a simple ExpressJS server to interact with the database.

Prisma simplifies database interactions by providing a type-safe and intuitive API, making it easier to build robust and scalable applications. Happy coding!