Implementing Design Patterns

export class UserRepository {
  constructor(private prisma: PrismaClient) {}
  findById(id: number) { return this.prisma.user.findUnique({ where: { id } }); }
  create(data: Prisma.UserCreateInput) { return this.prisma.user.create({ data }); }
}

await prisma.$transaction(async (tx) => {
  await new UserRepository(tx).create(userData);
  await new AuditRepository(tx).log("user.create");
});

// lib/prisma.ts
import { PrismaClient } from "@prisma/client";
const globalAny = global as any;
export const prisma: PrismaClient = globalAny.prisma ?? new PrismaClient();
if (process.env.NODE_ENV !== "production") globalAny.prisma = prisma;

class UserQuery {
  private args: Prisma.UserFindManyArgs = {};
  where(w: Prisma.UserWhereInput) { this.args.where = { ...this.args.where, ...w }; return this; }
  paginate(skip: number, take: number) { Object.assign(this.args, { skip, take }); return this; }
  exec(p: PrismaClient) { return p.user.findMany(this.args); }
}