This script will ensure that only one instance of Prisma client exists

prisma.ts

import { PrismaClient } from '@prisma/client';

declare global {
  namespace NodeJS {
    interface Global {}
  }
}

interface CustomNodeJsGlobal extends NodeJS.Global {
  prisma: PrismaClient;
}

declare const global: CustomNodeJsGlobal;

const prisma = global.prisma || new PrismaClient();

if (process.env.NODE_ENV === 'production') global.prisma = prisma;

export default prisma;