Introduction to Prisma Client

Prisma Client is an auto-generated and type-safe query builder that's tailored to your data. The easiest way to get started with Prisma Client is by following the Quickstart.

Quickstart (5 min)

Prerequisites

In order to set up Prisma Client, you need a Prisma Config and a Prisma schema file:

import 'dotenv/config';
import { defineConfig, env } from 'prisma/config';

export default defineConfig({
  schema: './prisma/schema.prisma',
  datasource: {
    url: env('DATABASE_URL'),
  },
});

Installation

Install the Prisma CLI, the Prisma Client library, and the driver adapter for your database:

npm install prisma --save-dev
npm install @prisma/client @prisma/adapter-pg pg

Generate the Client API

Prisma Client is based on the models in Prisma Schema. To provide the correct types, you need generate the client code:

npx prisma generate

This will create a generated directory based on where you set the output to in the Prisma Schema. Any time your import Prisma Client, it will need to come from this generated client API.

Importing Prisma Client

With the client generated, import it along with your driver adapter and create a new instance:

import { PrismaClient } from "./path/to/generated/prisma";
import { PrismaPg } from "@prisma/adapter-pg";

const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL!,
});

export const prisma = new PrismaClient({ adapter });

Find out what driver adapter is needed for your database.

Your application should generally only create one instance of PrismaClient. How to achieve this depends on whether you are using Prisma ORM in a long-running application or in a serverless environment.

Creating multiple instances of PrismaClient will create multiple connection pools and can hit the connection limit for your database. Too many connections may start to slow down your database and eventually lead to errors such as:

Error in connector: Error querying the database: db error: FATAL: sorry, too many clients already
   at PrismaClientFetcher.request

Use Prisma Client to send queries to your database

Once you have instantiated PrismaClient, you can start sending queries in your code:

// run inside `async` function
const newUser = await prisma.user.create({
  data: {
    name: "Alice",
    email: "alice@prisma.io",
  },
});

const users = await prisma.user.findMany();

Evolving your application

Whenever you make changes to your database that are reflected in the Prisma schema, you need to manually re-generate Prisma Client to update the generated code in your output directory:

npx prisma generate