Connecting and disconnecting

PrismaClient connects and disconnects from your data source using the following two methods:

• $connect()
• $disconnect()

In most cases, you do not need to explicitly call these methods. PrismaClient automatically connects when you run your first query, creates a connection pool, and disconnects when the Node.js process ends.

See the connection management guide for information about managing connections for different deployment paradigms (long-running processes and serverless functions).

$connect()

It is not necessary to call $connect() thanks to the lazy connect behavior: The PrismaClient instance connects lazily when the first request is made to the API ($connect() is called for you under the hood).

const prisma = new PrismaClient()

// run inside `async` function
await prisma.$connect()

$disconnect()

When you call $disconnect() , Prisma Client:

1. Runs the beforeExit hook
2. Ends the Query Engine child process and closes all connections

In a long-running application such as a GraphQL API, which constantly serves requests, it does not make sense to $disconnect() after each request - it takes time to establish a connection, and doing so as part of each request will slow down your application.

import { PrismaClient } from '@prisma/client'

const prisma = new PrismaClient()
const emailService = new EmailService()

async function main() {
  const allUsers = await prisma.user.findMany()
  const emails = allUsers.map((x) => x.email)

  await emailService.send(emails, 'Hello!')
}

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

Exit hooks

The beforeExit hook runs when Prisma is triggered externally (e.g. via a SIGINT signal) to shut down, and allows you to run code before the Client disconnects - for example, to issue queries as part of a graceful shutdown of a service:

const prisma = new PrismaClient()

prisma.$on('beforeExit', async () => {
  console.log('beforeExit hook')
  // PrismaClient still available
  await prisma.message.create({
    data: {
      message: 'Shutting down server',
    },
  })
})