REST API Example

This example shows how to implement a REST API using NestJS and Prisma Client. The example uses an SQLite database file with some initial dummy data which you can find at ./prisma/dev.db. The example was bootstrapped using the NestJS CLI command nest new rest-nestjs.

Getting started

1. Download example and install dependencies

Download this example:

npx try-prisma@latest --template orm/rest-nestjs

Install npm dependencies:

cd rest-nestjs
npm install

Alternative: Clone the entire repo

Clone this repository:

git clone [email protected]:prisma/prisma-examples.git --depth=1

Install npm dependencies:

cd prisma-examples/orm/rest-nestjs
npm install

[Optional] Switch database to Prisma Postgres

This example uses a local SQLite database by default. If you want to use to Prisma Postgres, follow these instructions (otherwise, skip to the next step):

1. Set up a new Prisma Postgres instance in the Prisma Data Platform Console and copy the database connection URL.

2. Update the datasource block to use postgresql as the provider and paste the database connection URL as the value for url:

   datasource db {
     provider = "postgresql"
     url      = "prisma+postgres://accelerate.prisma-data.net/?api_key=ey...."
   }

   Note: In production environments, we recommend that you set your connection URL via an environment variable, e.g. using a .env file.

3. Install the Prisma Accelerate extension:

   npm install @prisma/extension-accelerate
   

4. Add the Accelerate extension to the PrismaClient instance:

   + import { withAccelerate } from "@prisma/extension-accelerate"
   
   + const prisma = new PrismaClient().$extends(withAccelerate())

That's it, your project is now configured to use Prisma Postgres!

2. Create and seed the database

Run the following command to create your database. This also creates the User and Post tables that are defined in prisma/schema.prisma:

npx prisma migrate dev --name init

When npx prisma migrate dev is executed against a newly created database, seeding is also triggered. The seed file in prisma/seed.ts will be executed and your database will be populated with the sample data.

If you switched to Prisma Postgres in the previous step, you need to trigger seeding manually (because Prisma Postgres already created an empty database instance for you, so seeding isn't triggered):

npx prisma db seed

3. Start the REST API server

npm run dev

The server is now running on http://localhost:3000. You can now run the API requests, e.g. http://localhost:3000/feed.

Using the REST API

You can access the REST API of the server using the following endpoints:

GET

• /post/:id: Fetch a single post by its id
• /feed?searchString={searchString}&take={take}&skip={skip}&orderBy={orderBy}: Fetch all published posts
  • Query Parameters
    • searchString (optional): This filters posts by title or content
    • take (optional): This specifies how many objects should be returned in the list
    • skip (optional): This specifies how many of the returned objects in the list should be skipped
    • orderBy (optional): The sort order for posts in either ascending or descending order. The value can either asc or desc
• /user/:id/drafts: Fetch user's drafts by their id
• /users: Fetch all users

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
• /signup: Create a new user
  • Body:
    • email: String (required): The email address of the user
    • name: String (optional): The name of the user
    • postData: PostCreateInput[] (optional): The posts of the user

PUT

• /publish/:id: Toggle the publish value of a post by its id
• /post/:id/views: Increases the viewCount of a Post by one id

DELETE

• /post/:id: Delete a post by its id

Evolving the app

Evolving the application typically requires two steps:

1. Migrate your database using Prisma Migrate
2. Update your application code

For the following example scenario, assume you want to add a "profile" feature to the app where users can create a profile and write a short bio about themselves.

1. Migrate your database using Prisma Migrate

The first step is to add a new table, e.g. called Profile, to the database. You can do this by adding a new model to your Prisma schema file file and then running a migration afterwards:

// ./prisma/schema.prisma

model User {
  id      Int      @default(autoincrement()) @id
  name    String?
  email   String   @unique
  posts   Post[]
+ profile Profile?
}

model Post {
  id        Int      @id @default(autoincrement())
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
  title     String
  content   String?
  published Boolean  @default(false)
  viewCount Int      @default(0)
  author    User?    @relation(fields: [authorId], references: [id])
  authorId  Int?
}

+model Profile {
+  id     Int     @default(autoincrement()) @id
+  bio    String?
+  user   User    @relation(fields: [userId], references: [id])
+  userId Int     @unique
+}

Once you've updated your data model, you can execute the changes against your database with the following command:

npx prisma migrate dev --name add-profile

This adds another migration to the prisma/migrations directory and creates the new Profile table in the database.

2. Update your application code

You can now use your PrismaClient instance to perform operations against the new Profile table. Those operations can be used to implement API endpoints in the REST API.

2.1 Add the API endpoint to your app

Update your AppController class inside app.controller.ts file by adding a new endpoint to your API:

@Post('user/:id/profile')
async createUserProfile(
  @Param('id') id: string,
  @Body() userBio: { bio: string }
): Promise<Profile> {
  return this.prismaService.profile.create({
    data: {
      bio: userBio.bio,
      user: {
        connect: {
          id: Number(id)
        }
      }
    }
  })
}

At the top of app.controller.ts, update your imports to include Profile from @prisma/client as follows:

import { User as UserModel, Post as PostModel, Prisma, Profile } from '@prisma/client'

2.2 Testing out your new endpoint

Restart your application server and test out your new endpoint.

POST

• /user/:id/profile: Create a new profile based on the user id
  • Body:
    • bio: String : The bio of the user

Expand to view more sample Prisma Client queries on Profile

Here are some more sample Prisma Client queries on the new Profile model:

Create a new profile for an existing user

const profile = await prisma.profile.create({
  data: {
    bio: 'Hello World',
    user: {
      connect: { email: '[email protected]' },
    },
  },
})

Create a new user with a new profile

const user = await prisma.user.create({
  data: {
    email: '[email protected]',
    name: 'John',
    profile: {
      create: {
        bio: 'Hello World',
      },
    },
  },
})

Update the profile of an existing user

const userWithUpdatedProfile = await prisma.user.update({
  where: { email: '[email protected]' },
  data: {
    profile: {
      update: {
        bio: 'Hello Friends',
      },
    },
  },
})

Switch to another database (e.g. PostgreSQL, MySQL, SQL Server, MongoDB)

If you want to try this example with another database than SQLite, you can adjust the the database connection in prisma/schema.prisma by reconfiguring the datasource block.

Learn more about the different connection configurations in the docs.

Expand for an overview of example configurations with different databases

PostgreSQL

For PostgreSQL, the connection URL has the following structure:

datasource db {
  provider = "postgresql"
  url      = "postgresql://USER:PASSWORD@HOST:PORT/DATABASE?schema=SCHEMA"
}

Here is an example connection string with a local PostgreSQL database:

datasource db {
  provider = "postgresql"
  url      = "postgresql://janedoe:mypassword@localhost:5432/notesapi?schema=public"
}

MySQL

For MySQL, the connection URL has the following structure:

datasource db {
  provider = "mysql"
  url      = "mysql://USER:PASSWORD@HOST:PORT/DATABASE"
}

Here is an example connection string with a local MySQL database:

datasource db {
  provider = "mysql"
  url      = "mysql://janedoe:mypassword@localhost:3306/notesapi"
}

Microsoft SQL Server

Here is an example connection string with a local Microsoft SQL Server database:

datasource db {
  provider = "sqlserver"
  url      = "sqlserver://localhost:1433;initial catalog=sample;user=sa;password=mypassword;"
}

MongoDB

Here is an example connection string with a local MongoDB database:

datasource db {
  provider = "mongodb"
  url      = "mongodb://USERNAME:PASSWORD@HOST/DATABASE?authSource=admin&retryWrites=true&w=majority"
}

Next steps

• Check out the Prisma docs
• Share your feedback on the Prisma Discord
• Create issues and ask questions on GitHub