NodeJS:如何使用Loopback4处理多对多关系

import {Entity, model, property, hasMany} from 'loopback4';

@model()
export class User extends Entity {
  @property({
    type: 'string',
    id: true,
    generated: true,
  })
  id: string;

  @property({
    type: 'string',
    required: true,
  })
  name: string;

  @hasMany(() => Role)
  roles: Role[];
}

@model()
export class Role extends Entity {
  @property({
    type: 'string',
    id: true,
    generated: true,
  })
  id: string;

  @property({
    type: 'string',
    required: true,
  })
  name: string;

  @hasMany(() => User)
  users: User[];
}

import {DefaultCrudRepository, repository, HasManyRepositoryFactory} from 'loopback4';
import {User, Role} from '../models';
import {DbDataSource} from '../datasources';

export class UserRepository extends DefaultCrudRepository<User, typeof User.prototype.id> {
  public readonly roles: HasManyRepositoryFactory<Role, typeof User.prototype.id>;

  constructor(
    @inject('datasources.db') dataSource: DbDataSource,
    @repository.getter('RoleRepository') protected roleRepositoryGetter: Getter<RoleRepository>,
  ) {
    super(User, dataSource);
    this.roles = this.createHasManyRepositoryFactoryFor('roles', roleRepositoryGetter);
  }
}

const user = await userRepository.create({name: 'John'});
const role = await roleRepository.create({name: 'Admin'});

await userRepository.roles(user.id).create(role);