jawj/migrate-vercel-postgres-to-neon

Migrate @vercel/postgres to @neondatabase/serverless

This repo demonstrates migrating from Vercel Postgres (now deprecated) to Neon's serverless driver.

Note that, for new projects, we strongly recommend using @neondatabase/serverless driver API directly.

There are two main strategies:

(1) If you use only import { sql } from '@vercel/postgres', do this:

npm remove @vercel/postgres
npm install @neondatabase/serverless

Then replace all instances of

import { sql } from '@vercel/postgres'`

with

import { neon } from '@neondatabase/serverless'
const sql = neon(process.env.POSTGRES_URL!, { fullResults: true });  // remove the `!` if using plain JS, not TypeScript

(2) If you import and use any other features of @vercel/postgres -- such as db, createClient or createPool -- do this:

npm remove @vercel/postgres
npm install @neondatabase/serverless

Then, if you're using Vercel's Edge runtime (not Node.js):

• Copy vercel-postgres-compat.ts to your project (it's in the api folder here).

• Replace all instances of:

import { ... } from '@vercel/postgres';

with

import { ... } from './vercel-postgres-compat';  // add `.js` to filename if using plain JS, not TypeScript

Otherwise, if you're using Vercel's Node.js runtime:

npm install ws @types/ws  # remove @types/ws if using plain JS, not TypeScript

• Copy vercel-postgres-compat.ts and vercel-postgres-compat-node.ts to your project (they're in the api folder here).

• Replace all instances of:

import { ... } from '@vercel/postgres';

with

import { ... } from './vercel-postgres-compat-node';  // add `.js` to filename if using plain JS, not TypeScript

Deploy this repo

• Ensure the psql client is installed

• Create a Neon database and make a note of the connection string

• Clone this repo, then:

# get dependencies
npm install

# set up Vercel
npx vercel login
npx vercel link

# create POSTGRES_URL environment variable, remote and local
npx vercel env add POSTGRES_URL  # paste in the connection string: postgres://...
npx vercel env pull .env.local  # now bring it down into ./.env.local for local use

# create the schema and copy data to DB
(source .env.local \
  && echo "CREATE TABLE posts (id serial primary key, body text not null); INSERT INTO posts (body) VALUES ('Post 1'), ('Post 2');" \
  | psql $DATABASE_URL)

# ... and deploy
npx vercel deploy

• Now visit the deployed app