## Introduction

This guide shows you how to use Prisma ORM with [NestJS](https://nestjs.com/), a progressive Node.js framework for building efficient and scalable server-side applications. You'll build a REST API with NestJS that uses Prisma ORM to store and retrieve data from a database.

[Prisma ORM](https://www.prisma.io) is an open-source ORM for Node.js and TypeScript. It is used as an **alternative** to writing plain SQL, or using another database access tool such as SQL query builders (like [knex.js](https://knexjs.org/)) or ORMs (like [TypeORM](https://typeorm.io/) and [Sequelize](https://sequelize.org/)). Prisma currently supports PostgreSQL, MySQL, SQL Server, SQLite, MongoDB and CockroachDB.

While Prisma can be used with plain JavaScript, it embraces TypeScript and provides a level of type-safety that goes beyond the guarantees other ORMs in the TypeScript ecosystem offer.

You can find a ready-to-run example [here](https://github.com/prisma/prisma-examples/tree/latest/orm/nest)

## Prerequisites

- [Node.js 20+](https://nodejs.org)

## 1. Create your NestJS project

Install the NestJS CLI and create a new project:

```terminal
npm install -g @nestjs/cli
nest new nestjs-prisma
```

When prompted, select **npm** as your package manager. Navigate to the project directory:

```terminal
cd nestjs-prisma
```

You can run `npm start` to start your application at `http://localhost:3000/`. Over the course of this guide, you'll add routes to store and retrieve data about _users_ and _posts_.

In `package.json`, add the `type` field set to `"module"`:

```json file=package.json
{
  // add-next-line
  "type": "module"
}
```

## 2. Set up Prisma

### 2.1. Install Prisma and dependencies

Install the necessary Prisma packages and database drivers:

```terminal
npm install prisma --save-dev
npm install @prisma/client @prisma/adapter-pg pg
```

:::info

If you are using a different database provider (PostgreSQL, MySQL, SQL Server), install the corresponding driver adapter package instead of `@prisma/adapter-pg`. For more information, see [Database drivers](/orm/overview/databases/database-drivers).

:::

### 2.2. Initialize Prisma

Initialize Prisma in your project:

```terminal
npx prisma init --db --output ../src/generated/prisma
```

This creates a new `prisma` directory with the following contents:

- `schema.prisma`: Specifies your database connection and contains the database schema
- `prisma.config.ts`: A configuration file for your projects
- `.env`: A [dotenv](https://github.com/motdotla/dotenv) file, typically used to store your database credentials in a group of environment variables

### 2.3. Set the generator output path

Specify your output `path` for the generated Prisma client by either passing `--output ../src/generated/prisma` during `prisma init` or directly in your Prisma schema:

```prisma file=prisma/schema.prisma
generator client {
  provider = "prisma-client"
  output   = "../src/generated/prisma"
}
```

### 2.4. Configure your database connection

Your database connection is configured in the `datasource` block in your `schema.prisma` file. By default it's set to `postgresql` which is what you need for this guide.

```prisma file=prisma/schema.prisma
generator client {
  provider = "prisma-client"
  output   = "../src/generated/prisma"
}

datasource db {
  provider = "postgresql"
}
```

Now, open up `.env` and you should see a `DATABASE_URL` already specified:

```bash file=.env
DATABASE_URL=""
```
:::note

Make sure you have a [ConfigModule](https://docs.nestjs.com/techniques/configuration) configured, otherwise the `DATABASE_URL` variable will not be picked up from `.env`.

:::

### 2.5. Define your data model

Add the following two models to your `schema.prisma` file:

```prisma file=prisma/schema.prisma
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?
}
```

### 2.6. Create and run your migration

With your Prisma models in place, you can generate your SQL migration files and run them against the database. Run the following commands in your terminal:

```terminal
npx prisma migrate dev --name init
```

This `prisma migrate dev` command generates SQL files and directly runs them against the database. In this case, the following migration files was created in the existing `prisma` directory:

```bash
$ tree prisma
prisma
├── migrations
│   └── 20201207100915_init
│       └── migration.sql
└── schema.prisma
```

### 2.7. Generate Prisma Client

Once installed, you can run the generate command to generate the types and Client needed for your project. If any changes are made to your schema, you will need to rerun the `generate` command to keep those types in sync.

```terminal
npx prisma generate
```

## 3. Create a Prisma service

You're now able to send database queries with Prisma Client. When setting up your NestJS application, you'll want to abstract away the Prisma Client API for database queries within a service. To get started, you can create a new `PrismaService` that takes care of instantiating `PrismaClient` and connecting to your database.

Inside the `src` directory, create a new file called `prisma.service.ts` and add the following code to it:

```typescript file=src/prisma.service.ts
import { Injectable } from '@nestjs/common';
import { PrismaClient } from './generated/prisma/client.js';
import { PrismaPg } from '@prisma/adapter-pg';

@Injectable()
export class PrismaService extends PrismaClient {
  constructor() {
    const adapter = new PrismaPg({
      connectionString: process.env.DATABASE_URL as string,
    });
    super({ adapter });
  }
}
```

## 4. Create User and Post services

Next, you can write services that you can use to make database calls for the `User` and `Post` models from your Prisma schema.

### 4.1. Create the User service

Still inside the `src` directory, create a new file called `user.service.ts` and add the following code to it:

```typescript file=src/user.service.ts
import { Injectable } from '@nestjs/common';
import { PrismaService } from './prisma.service.js';
import { User, Prisma } from './generated/prisma/client.js';

@Injectable()
export class UserService {
  constructor(private prisma: PrismaService) {}

  async user(
    userWhereUniqueInput: Prisma.UserWhereUniqueInput,
  ): Promise<User | null> {
    return this.prisma.user.findUnique({
      where: userWhereUniqueInput,
    });
  }

  async users(params: {
    skip?: number;
    take?: number;
    cursor?: Prisma.UserWhereUniqueInput;
    where?: Prisma.UserWhereInput;
    orderBy?: Prisma.UserOrderByWithRelationInput;
  }): Promise<User[]> {
    const { skip, take, cursor, where, orderBy } = params;
    return this.prisma.user.findMany({
      skip,
      take,
      cursor,
      where,
      orderBy,
    });
  }

  async createUser(data: Prisma.UserCreateInput): Promise<User> {
    return this.prisma.user.create({
      data,
    });
  }

  async updateUser(params: {
    where: Prisma.UserWhereUniqueInput;
    data: Prisma.UserUpdateInput;
  }): Promise<User> {
    const { where, data } = params;
    return this.prisma.user.update({
      data,
      where,
    });
  }

  async deleteUser(where: Prisma.UserWhereUniqueInput): Promise<User> {
    return this.prisma.user.delete({
      where,
    });
  }
}
```

Notice how you're using Prisma Client's generated types to ensure that the methods that are exposed by your service are properly typed. You therefore save the boilerplate of typing your models and creating additional interface or DTO files.

### 4.2. Create the Post service

Now do the same for the `Post` model.

Still inside the `src` directory, create a new file called `post.service.ts` and add the following code to it:

```typescript file=src/post.service.ts

import { Injectable } from '@nestjs/common';
import { PrismaService } from './prisma.service.js';
import { Post, Prisma } from './generated/prisma/client.js';

@Injectable()
export class PostService {
  constructor(private prisma: PrismaService) {}

  async post(
    postWhereUniqueInput: Prisma.PostWhereUniqueInput,
  ): Promise<Post | null> {
    return this.prisma.post.findUnique({
      where: postWhereUniqueInput,
    });
  }

  async posts(params: {
    skip?: number;
    take?: number;
    cursor?: Prisma.PostWhereUniqueInput;
    where?: Prisma.PostWhereInput;
    orderBy?: Prisma.PostOrderByWithRelationInput;
  }): Promise<Post[]> {
    const { skip, take, cursor, where, orderBy } = params;
    return this.prisma.post.findMany({
      skip,
      take,
      cursor,
      where,
      orderBy,
    });
  }

  async createPost(data: Prisma.PostCreateInput): Promise<Post> {
    return this.prisma.post.create({
      data,
    });
  }

  async updatePost(params: {
    where: Prisma.PostWhereUniqueInput;
    data: Prisma.PostUpdateInput;
  }): Promise<Post> {
    const { data, where } = params;
    return this.prisma.post.update({
      data,
      where,
    });
  }

  async deletePost(where: Prisma.PostWhereUniqueInput): Promise<Post> {
    return this.prisma.post.delete({
      where,
    });
  }
}
```

Your `UserService` and `PostService` currently wrap the CRUD queries that are available in Prisma Client. In a real world application, the service would also be the place to add business logic to your application. For example, you could have a method called `updatePassword` inside the `UserService` that would be responsible for updating the password of a user.

## 5. Implement REST API routes

### 5.1. Create the controller

Finally, you'll use the services you created in the previous sections to implement the different routes of your app. For the purpose of this guide, you'll put all your routes into the already existing `AppController` class.

Replace the contents of the `app.controller.ts` file with the following code:

```typescript file=src/app.controller.ts
import {
  Controller,
  Get,
  Param,
  Post,
  Body,
  Put,
  Delete,
} from '@nestjs/common';
import { UserService } from './user.service.js';
import { PostService } from './post.service.js';
import { User as UserModel } from './generated/prisma/client.js';
import { Post as PostModel } from './generated/prisma/client.js';

@Controller()
export class AppController {
  constructor(
    private readonly UserService: UserService,
    private readonly postService: PostService,
  ) {}

  @Get('post/:id')
  async getPostById(@Param('id') id: string): Promise<PostModel | null> {
    return this.postService.post({ id: Number(id) });
  }

  @Get('feed')
  async getPublishedPosts(): Promise<PostModel[]> {
    return this.postService.posts({
      where: { published: true },
    });
  }

  @Get('filtered-posts/:searchString')
  async getFilteredPosts(
    @Param('searchString') searchString: string,
  ): Promise<PostModel[]> {
    return this.postService.posts({
      where: {
        OR: [
          {
            title: { contains: searchString },
          },
          {
            content: { contains: searchString },
          },
        ],
      },
    });
  }

  @Post('post')
  async createDraft(
    @Body() postData: { title: string; content?: string; authorEmail: string },
  ): Promise<PostModel> {
    const { title, content, authorEmail } = postData;
    return this.postService.createPost({
      title,
      content,
      author: {
        connect: { email: authorEmail },
      },
    });
  }

  @Post('user')
  async signupUser(
    @Body() userData: { name?: string; email: string },
  ): Promise<UserModel> {
    return this.UserService.createUser(userData);
  }

  @Put('publish/:id')
  async publishPost(@Param('id') id: string): Promise<PostModel> {
    return this.postService.updatePost({
      where: { id: Number(id) },
      data: { published: true },
    });
  }

  @Delete('post/:id')
  async deletePost(@Param('id') id: string): Promise<PostModel> {
    return this.postService.deletePost({ id: Number(id) });
  }
}
```

This controller implements the following routes:

#### `GET`

- `/post/:id`: Fetch a single post by its `id`
- `/feed`: Fetch all _published_ posts
- `/filtered-posts/:searchString`: Filter posts by `title` or `content`

#### `POST`

- `/post`: Create a new post
  - Body:
    - `title: String` (required): The title of the post
    - `content: String` (optional): The content of the post
    - `authorEmail: String` (required): The email of the user that creates the post
- `/user`: Create a new user
  - Body:
    - `email: String` (required): The email address of the user
    - `name: String` (optional): The name of the user

#### `PUT`

- `/publish/:id`: Publish a post by its `id`

#### `DELETE`

- `/post/:id`: Delete a post by its `id`

### 5.2. Register services in the app module

Remember to register the new services in the app module.

Update `src/app.module.ts` to register all services:

```typescript file=src/app.module.ts
import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { ConfigModule } from '@nestjs/config';
import { AppService } from './app.service.js';
//add-start
import { PrismaService } from './prisma.service.js';
import { UserService } from './user.service.js';
import { PostService } from './post.service.js';
//add-end

@Module({
  imports: [ConfigModule.forRoot()],
  controllers: [AppController],
  //add-next-line
  providers: [AppService, PrismaService, UserService, PostService],
})
export class AppModule {}
```

## 6. Test your API

Start your application:

```terminal
npm start
```

Test your endpoints with curl, [Postman](https://www.postman.com/), or [HTTPie](https://httpie.io/).

**Create a user:**
```bash
curl -X POST http://localhost:3000/user \
  -H "Content-Type: application/json" \
  -d '{"name": "Alice", "email": "alice@prisma.io"}'
```

**Create a post:**
```bash
curl -X POST http://localhost:3000/post \
  -H "Content-Type: application/json" \
  -d '{"title": "Hello World", "authorEmail": "alice@prisma.io"}'
```

**Get published posts:**
```bash
curl http://localhost:3000/feed
```

**Publish a post:**
```bash
curl -X PUT http://localhost:3000/publish/1
```

**Search posts:**
```bash
curl http://localhost:3000/filtered-posts/hello
```

## Summary

In this guide, you learned how to use Prisma ORM with NestJS to implement a REST API. The controller that implements the routes of the API is calling a `PrismaService` which in turn uses Prisma Client to send queries to a database to fulfill the data needs of incoming requests.

If you want to learn more about using NestJS with Prisma, be sure to check out the following resources:

- [NestJS & Prisma](https://www.prisma.io/nestjs)
- [Ready-to-run example projects for REST & GraphQL](https://github.com/prisma/prisma-examples/)
- [Production-ready starter kit](https://github.com/notiz-dev/nestjs-prisma-starter#instructions)
- [Video: Accessing Databases using NestJS with Prisma (5min)](https://www.youtube.com/watch?v=UlVJ340UEuk&ab_channel=Prisma) by [Marc Stammerjohann](https://github.com/marcjulian)

---

# How to use Prisma ORM and Prisma Postgres with Elysia