db.ts

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

declare global {
  // allow global `var` declarations
  // eslint-disable-next-line no-var
  var prisma:
    | PrismaClient<{ log: [{ level: 'query'; emit: 'event' }] }>
    | undefined;
}

export const prisma =
  global.prisma ||
  new PrismaClient({ log: [{ level: 'query', emit: 'event' }] });

if (process.env.NODE_ENV !== 'production') global.prisma = prisma;
prisma.$on('query', console.log);