use prisma client in Next.js

const prismaClientSingleton = () => {
  return new PrismaClient();
};
 
declare const globalThis: {
  __db__: ReturnType<typeof prismaClientSingleton>;
} & typeof global;
 
const db = globalThis.__db__ ?? prismaClientSingleton();
 
if (process.env.NODE_ENV === 'development') {
  globalThis.__db__ = db;
}
 
export default db;

globalThis에 대해서 더 알고 싶다면 global vs globalThis.