Easy REST and GraphQL with Prisma

Prisma is an Object to Relational Mapper (ORM) that makes working with databases more accessible and consistent. Prisma supports both Relational Databases like PostgreSQL and Document Databases MongoDB.

Let’s use Prisma to see how we can set up a simple REST API and a GrapgQL API for the same data model. We will use a model with one-to-one, one-to-many, and many-to-many relationships to see how these are managed in the ORM.

Model

Authorbooks (many)
- biography (one)
Biography
- subject (one)
Book
- author (one)
- category (many)
Category
- book (many)

Relationships

‘one-to-one’ relationship is Author to Biography
‘one-to-many’ relationship is Author to Books
‘many-to-many’ relationship is Categories to Books

We will tackle this in 5 parts.

Run Relational Database locally.
Implement CRUD (Create Read Update Delete) on the Book model with Prisma.
Add additional models and relationships.
Create a REST API with the Book Model.
Create a GraphQL API with the Book Model.

Run Relational Database locally.

We will use PostgreSQL running in a Docker container to make this easy.

To start the Database, run:

docker-compose up -d

To Confirm the Database is running, run:

docker exec -it prism-example bash
psql -U test
\l
\q
exit

To stop the Database, run:

docker-compose down

Implement CRUD (Create Read Update Delete) on the Book model with Prisma.

Initialize project and install dependencies

npm init -y
npm install --save-dev prisma typescript ts-node @types/node
npm install --save-dev nodemon

Setup Typescript

Documentation to configure typescript for Prisma is here

Create tsconfig.json

touch tsconfig.json

Add this

{
  "compilerOptions": {
    "sourceMap": true,
    "outDir": "dist",
    "strict": true,
    "lib": ["esnext"],
    "esModuleInterop": true
  }
}

Install VSCode Prisma extension

The extension you want is Prisma v4.2.0

To enable, add the following to the VSCode settings JSON file. To get to the settings, go here: Code > Preferences > Settings, then switch to the JSON view in the upper right.

  "[prisma]": {
    "editor.formatOnSave": true,
    "editor.defaultFormatter": "Prisma.prisma"
  }

Initialize Prisma

npx prisma init

update .env

DATABASE_URL="postgresql://test:test@localhost:5432/test?schema=public"

Add the book Model

// prisma/schema.prisma

// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

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

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

model Author {
  id          String  @id @default(uuid())
  title       String  @unique
  description String?
}

Let Prisma set up the Database, and let’s see what we have.

npx prisma migrate dev
npx prisma studio

Now let’s use prisma-client to access the Database.

npm install @prisma/client
npx prisma generate

Create our node app

mkdir src && touch src/app.ts

Add this

// src/app.ts
import { PrismaClient } from "@prisma/client";

const prisma = new PrismaClient();

async function main() {
  console.log(
    await prisma.book.create({
      data: {
        title: "My First Book",
      },
    })
  );
}

main()
  .catch((e) => {
    console.log(e);
  })
  .finally(async () => {
    await prisma.$disconnect();
  });

Now we need a way to run our Node application, so edit package.json.

  "scripts": {
    "dev:simple": "nodemon ./src/app.ts",
...

Add run it

npm run dev:simple

Let’s try full CRUD. Edit src/app.ts .

async function main() {
  // remove all
  await prisma.book.deleteMany();
  const firstBook = await prisma.book.create({
    data: {
      title: "My First Book",
    },
  });
  console.log("After adding First book.", await prisma.book.findMany());
  const firstBookUpdates = await prisma.book.update({
    where: { id: firstBook.id },
    data: {
      title: "My First Book!!!",
    },
  });
  console.log("After updating First book.", await prisma.book.findMany());
  await prisma.book.delete({
    where: { id: firstBook.id },
  });
  console.log("After deleting First book.", await prisma.book.findMany());
}

Add additional models and relationships.

Let’s build a richer schema.

// prisma/schema.prisma

// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

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

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

model Author {
  id        String     @id @default(uuid())
  name      String     @unique
  books     Book[]
  biography Biography?
}

model Biography {
  id       String   @id @default(uuid())
  dob      DateTime
  author   Author   @relation(fields: [authorId], references: [id])
  authorId String   @unique
}

model Book {
  id          String     @id @default(uuid())
  title       String     @unique
  description String?
  author      Author?    @relation(fields: [authorId], references: [id])
  authorId    String?
  categories  Category[]
}

model Category {
  id    String @id @default(uuid())
  name  String @unique
  books Book[]
}

We can seed the Database for our testing by creating a seed file and pointing to it in package.json.

Add this to package.json.

  "prisma": {
    "seed": "ts-node prisma/seed.ts"
  }

Create this seed script.

// prisma/seed.ts
import { PrismaClient } from "@prisma/client";

const prisma = new PrismaClient();

async function seed() {
  // create Categories
  const [fiction, nonFiction] = await Promise.all([
    prisma.category.create({
      data: {
        name: "fiction",
      },
    }),
    prisma.category.create({
      data: {
        name: "non-fiction",
      },
    }),
  ]);

  // create Author and Biography
  const markTwain = await prisma.author.create({
    data: {
      name: "Mark Twain",
      biography: {
        create: {
          dob: new Date("November 30, 1835"),
        },
      },
    },
  });

  // create books
  await Promise.all([
    prisma.book.create({
      data: {
        title: "The Adventures of Tom Sawyer",
        authorId: markTwain.id,
        categories: { connect: { id: fiction.id } },
        description:
          "The Adventures of Tom Sawyer is an 1876 novel by Mark Twain about a boy growing up along the Mississippi River. It is set in the 1840s in the town of St. Petersburg, which is based on Hannibal, Missouri, where Twain lived as a boy.",
      },
    }),
    prisma.book.create({
      data: {
        title: "Adventures of Huckleberry Finn",
        authorId: markTwain.id,
        categories: { connect: { id: fiction.id } },
        description:
          "The Adventures of Huckleberry Finn, is a novel by American author Mark Twain, which was first published in the United Kingdom in December 1884 and in the United States in February 1885.",
      },
    }),
  ]);
}

seed()
  .catch((e) => {
    console.log(e);
  })
  .finally(async () => {
    await prisma.$disconnect();
  });

Run the script and verify the results.

npx prisma migrate reset
npx prisma studio

Create a REST API with the Book Model.

For the REST API, we will use Fastify, so let’s install the dependencies.

npm install fastify

Create our REST API Application.

// src/rest.ts
import Fastify from "fastify";
const server = Fastify({
  logger: true,
});
import authorV1Routes from "./modules/author/author.v1.routes";
import bookV1Routes from "./modules/book/book.v1.routes";

async function main() {
  server.register(authorV1Routes, { prefix: "/v1" });
  server.register(bookV1Routes, { prefix: "/v1" });

  // Run the server!
  server.listen({ port: 3000 }, function(err, address) {
    if (err) {
      server.log.error(err);
      process.exit(1);
    }
    console.log(`Server is now listening on ${address}`);
  });
}
main();

Add some Routes

// src/modules/author/author.v1.routes.ts

import { FastifyInstance } from "fastify";
import { PrismaClient } from "@prisma/client";

const prisma = new PrismaClient();

async function authorRoutes(server: FastifyInstance) {
  server.get("/author", async function(request, reply) {
    reply.send(await prisma.author.findMany());
  });
  server.post("/author", async (request, reply) => {
    const user = request.body as AuthorCreate;
    reply.send(
      await prisma.author.create({
        data: {
          name: user.name,
        },
      })
    );
  });
  server.put("/author", async (request, reply) => {
    const author = request.body as AuthorUpdate;
    reply.send(
      await prisma.author.update({
        data: {
          name: author.name,
        },
        where: { id: author.id },
      })
    );
  });
  server.delete("/author", async (request, reply) => {
    const author = request.body as AuthorDelete;
    reply.send(
      await prisma.author.delete({
        where: { id: author.id },
      })
    );
  });
}

export default authorRoutes;

interface AuthorCreate {
  name: string;
}
interface AuthorDelete {
  id: string;
}
interface AuthorUpdate {
  id: string;
  name: string;
}

// src/modules/user/book.v1.routes.ts

import { FastifyInstance } from "fastify";
import { PrismaClient } from "@prisma/client";

const prisma = new PrismaClient();

async function bookRoutes(server: FastifyInstance) {
  server.get("/book", async function(request, reply) {
    reply.send(await prisma.book.findMany());
  });
  server.post("/book", async (request, reply) => {
    const book = request.body as BookCreate;
    reply.send(
      await prisma.book.create({
        data: {
          title: book.title,
          description: book.description,
        },
      })
    );
  });
  server.put("/book", async (request, reply) => {
    const book = request.body as BookUpdate;
    reply.send(
      await prisma.book.update({
        data: {
          title: book.title,
          description: book.description,
        },
        where: { id: book.id },
      })
    );
  });
  server.delete("/book", async (request, reply) => {
    const book = request.body as BookDelete;
    reply.send(
      await prisma.book.delete({
        where: { id: book.id },
      })
    );
  });
}

export default bookRoutes;

interface BookCreate {
  title: string;
  description?: string;
}
interface BookDelete {
  id: string;
}
interface BookUpdate {
  id: string;
  title: string;
  description?: string;
}

Create a script in package.json.

  "scripts": {
    "dev:rest": "ts-node ./src/rest.ts",
...

Run and test it.

npm run dev:rest
curl --request GET  --url http://localhost:3000/v1/book

Create a GraphQL API.

Install dependencies

npm install type-graphql graphql-fields class-validator ref
lect-metadata graphql apollo-server
npm install --save-dev typegraphql-prisma

Add generator to schema-prism.

generator typegraphql {
  provider = "typegraphql-prisma"
}

Generate

npx prisma generate

Create our App

// src/typeGraphql.ts
import "reflect-metadata";
import { PrismaClient } from "@prisma/client";
import { ApolloServer } from "apollo-server";
import { resolvers } from "@generated/type-graphql";
import * as tq from "type-graphql";

const prisma = new PrismaClient();

const app = async () => {
  const schema = await tq.buildSchema({ resolvers, emitSchemaFile: true });
  const server = new ApolloServer({
    schema,
    context: { prisma },
  });
  server.listen().then(async ({ url }) => {
    console.log(`Server ready at: ${url}`);
  });
};

app();

Add a run script in package.json.

  "scripts": {
    "dev:graphql": "ts-node ./src/typeGraphql.ts",

Open a browser here

Extra

Let’s go back to the REST example and use Zod to do some validation.