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

const prisma = new PrismaClient();

export class UserRepository {
  async findById(id: number) {
    return prisma.user.findUnique({
      where: { id }
    });
  }

  async create(data: { name: string; email: string }) {
    return prisma.user.create({ data });
  }

  async findWithPosts(id: number) {
    return prisma.user.findUnique({
      where: { id },
      include: { posts: true }
    });
  }
}

import { UserRepository } from './user.repository';

export class UserService {
  constructor(private repo = new UserRepository()) {}

  async registerUser(data: { name: string; email: string }) {
    const exists = await this.repo.findByEmail(data.email);
    if (exists) throw new Error('User already exists');

    return this.repo.create(data);
  }
}

await prisma.$transaction(async (tx) => {
  const user = await tx.user.create({ data: { name: 'A' } });
  await tx.post.create({ data: { title: 'B', userId: user.id } });
});

src/
  modules/
    user/
      user.controller.ts
      user.service.ts
      user.repository.ts
  prisma/
    schema.prisma
  common/
    utils/
    dto/