03 Use Prisma Api From Code D001

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export const meta = { title: 'Use Prisma API from Code', position: 3, nextText: 'Bonkerz! 💯 With everything you learned so far, you're now able to build a GraphQL server with Prisma and Prisma bindings. Let's go!' }

Goals

On this page, you will learn how to:

• Download the GraphQL schema of your Prisma API using the GraphQL CLI
• Create a Prisma binding for your Prisma API
• Use the Prisma binding to send queries and mutations to your Prisma API

The Prisma API is a GraphQL API that's served via HTTP. You can therefore consume it using any HTTP tool you like, such as curl or JavaScript's fetch (learn more). On this page, you're using Prisma bindings which provide a convenient abstraction on top of fetch to reduce boilerplate and improve the developer experience when working with Prisma.

Setup Node.JS project

For this tutorial, you'll use an extremely simple setup for your Node.JS app. Create your project in a directory called myapp using the following commands; note that myapp should not be located inside the hello-world directory which holds the service configuration of your service:

mkdir myapp
cd myapp
touch index.js
yarn init -y

Install Prisma bindings

Go ahead and add the Prisma binding dependency to your project:

yarn add prisma-binding graphql

Download the GraphQL schema of your Prisma API

When using Prisma bindings in your project, you need to have access to the auto-generated GraphQL schema of your Prisma API.

Download the GraphQL schema using the following command from the GraphQL CLI; you need to replace the __YOUR_PRISMA_ENDPOINT__-placeholder with the actual endpoint of your Prisma API (which you can find in your prisma.yml).

npx graphql get-schema --endpoint __YOUR_PRISMA_ENDPOINT__ --output prisma.graphql --no-all

The GraphQL schema is now stored in prisma.graphql (as specified in the --output parameter of the command).

Instantiate Prisma API using Prisma bindings

Prisma bindings provide a convenient way to interact with Prisma APIs. Instead of manually constructing HTTP requests and sending them to Prisma, you can use the auto-generated binding functions to send queries and mutations.

Instantiate a Prisma binding

It's time to write some code! Add the following snippet into index.js; like in the previous step you need to replace the ≥__YOUR_PRISMA_ENDPOINT__-placeholder with your actual endpoint:

const { Prisma } = require('prisma-binding')

const prisma = new Prisma({
  typeDefs: 'prisma.graphql',
  endpoint: '__YOUR_PRISMA_ENDPOINT__'
})

Use your Prisma binding to send queries and mutations

Add the following code snippet after the code you have added in the previous step:

// send `users` query
prisma.query.users({}, `{ id name }`)
  .then(users => console.log(users))
  .then(() =>
    // send `createUser` mutation
    prisma.mutation.createUser(
      {
        data: { name: `Sarah` },
      },
      `{ id name }`,
    ),
  )
  .then(newUser => {
    console.log(newUser)
    return newUser
  })
  .then(newUser =>
    // send `user` query
    prisma.query.user(
      {
        where: { id: newUser.id },
      },
      `{ name }`,
    ),
  )
  .then(user => console.log(user))

Here is a sequential overview of the tasks performed by the Node script:

1. Fetch all Users from the Prisma API using the users query (line 2):

query {
  users {
    id
    name
  }
}

1. Print the data that was received from the Prisma API using console.log (line 3).
2. Create a new User using the createUser mutation (line 6):

mutation {
  createUser(data: {
    name: "Sarah"
  }) {
    id
    name
  }
}

1. Print the data of the newly created User that was received from the Prisma API using console.log (line 13).
2. Fetch the newly created User using the user query (line 18):

query {
  user(where: {
    id: $id # the `id` parameter is provided as `newUser.id` in the binding function
  }) {
    name
  }
}

Execute the Node.JS script

To run the script and actually send the above queries and mutations to your Prisma service, run the following command:

node index.js

The expected output looks similar to this:

[]
{ id: 'cjjya4inyel970b296r43qwhn', name: 'Sarah' }
{ name: 'Sarah' }

If you already created some Users in your Prisma service, the array that's printed in the first line will not be empty.