This example shows how to implement a REST API with TypeScript using Express and Prisma Client. The example uses an SQLite database file with some initial dummy data which you can find at ./prisma/dev.db.

Download this example:

npx try-prisma --template typescript/rest-express

Install npm dependencies:

cd rest-express
npm install

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

cd prisma-examples/typescript/rest-express
npm install

Run the following command to create your SQLite database file. 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.

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.

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

• /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: 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

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

• /post/:id: Delete a post by its id

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.

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.

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.

Update your index.ts file by adding a new endpoint to your API:

app.post('/user/:id/profile', async (req, res) => {
  const { id } = req.params
  const { bio } = req.body

  const profile = await prisma.profile.create({
    data: {
      bio,
      user: {
        connect: {
          id: Number(id)
        }
      }
    }
  })

  res.json(profile)
})

Restart your application server and test out your new endpoint.

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

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

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

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

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.

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

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

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

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

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

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

• Check out the Prisma docs
• Share your feedback in the #product-wishlist channel on the Prisma Slack
• Create issues and ask questions on GitHub
• Watch our biweekly "What's new in Prisma" livestreams on Youtube