NestJs使用连接表更新多对多关系

import { Entity, PrimaryGeneratedColumn, Column, ManyToMany, JoinTable } from 'typeorm';
import { Role } from './role.entity';

@Entity()
export class User {
  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  name: string;

  @ManyToMany(type => Role)
  @JoinTable()
  roles: Role[];
}

@Entity()
export class Role {
  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  name: string;

  @ManyToMany(type => User, user => user.roles)
  users: User[];
}

import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User } from './user.entity';
import { Role } from './role.entity';

@Injectable()
export class UserService {
  constructor(
    @InjectRepository(User)
    private readonly userRepository: Repository<User>,
  ) {}

  async updateRoles(userId: number, roleIds: number[]): Promise<User> {
    const user = await this.userRepository.findOne(userId, { relations: ['roles'] });
    const roles = await this.roleRepository.findByIds(roleIds);

    user.roles = roles;
    return await this.userRepository.save(user);
  }
}