Set up Prisma

Goals

On this page, you will learn how to:

• Install the Prisma CLI
• Set up Prisma using Docker
• Introspect your existing database and derive a datamodel
• Use the datamodel to configure your Prisma API
• Generate a Prisma client
• Read and write data using the Prisma client

Install the Prisma CLI

The Prisma CLI is used for various Prisma workflows. You can install it using Homebrew or NPM:

brew tap prisma/prisma
brew install prisma
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Install Docker

To use Prisma locally, you need to have Docker installed on your machine. If you don't have Docker yet, you can download the Docker Community Edition for your operating system here.

Set up Prisma

Run the following command to connect Prisma to your existing database:

prisma init hello-world
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This launches an interactive wizard. Here's what you need to do:

1. Select Use existing database
2. Select your database, either PostgreSQL or MongoDB
3. Provide the connection details for your database (see below for more info)
4. Select the Prisma TypeScript client

Launch Prisma

To start Prisma and connect it to your database, run the following commands:

cd hello-world
docker-compose up -d
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Prisma is now connected to your database and runs on http://localhost:4466.

Deploy the Prisma datamodel

You now have the minimal setup ready to deploy your Prisma datamodel. Run the following command (this does not change anything in your database):

prisma deploy
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Prepare TypeScript application

Create your tsconfig.json with the following command:

touch tsconfig.json
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Add the following configuration to the tsconfig.json file:

{
  "compilerOptions": {
    "lib": ["es2016", "esnext.asynciterable"]
  }
}
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Next, initialize an empty NPM project in the current directory and install the required dependencies:

npm init -y
npm install --save prisma-client-lib
npm install --save-dev typescript ts-node
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Almost done! Run the following command to create an empty TypeScript script:

touch index.ts
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Great, you're now ready to write some code and talk to your database programmatically!

Read and write data using the Prisma client

The API operations of the Prisma client depend on the datamodel that was generated from the database introspection. The following sample queries assume there is a User type in the datamodel defined as follows:

type User {
  id: ID! @unique
  name: String!
}

If you don't have such a User type, you need to adjust the following code snippets with a type that matches your datamodel.

Add the following code in index.ts:

import { prisma } from './generated/prisma-client'

// A `main` function so that we can use async/await
async function main() {
  // Create a new user called `Alice`
  const newUser = await prisma.createUser({ name: 'Alice' })
  console.log(`Created new user: ${newUser.name} (ID: ${newUser.id})`)

  // Read all users from the database and print them to the console
  const allUsers = await prisma.users()
  console.log(allUsers)
}

main().catch(e => console.error(e))
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Before executing the code, go ahead and add a start script to package.json so you can comfortably run the code:

{
  "name": "hello-world",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo "Error: no test specified" && exit 1",
    "start": "ts-node index.ts"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "graphql": "^14.0.2",
    "prisma-client-lib": "^1.20.0"
  },
  "devDependencies": {
    "ts-node": "^7.0.1",
    "typescript": "^3.1.6"
  }
}
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Now execute the script with the following command:

npm run start
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Whenever you run the script with that command, a new user record is created in the database (because of the call to createUser).

Feel free to play around with the Prisma client API and try out some of the following operations by adding the following code snippets to the file (at the end of the main function) and re-executing the script:

const user = await prisma.user({ id: '__USER_ID__' })
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In some snippets, you need to replace the __USER__ID__ placeholder with the ID of an actual user.