TypeORM+NestJS查询User时无法获取关联Shop实体的问题求助

我使用TypeORM和NestJS搭建服务，User类与Shop类为一对一关系，外键shopId存储在User表中。但调用查询方法获取User时，关联的Shop对象并未被返回，仅得到User自身字段，求问题原因及解决办法。

User类代码 #

@Entity()
export class User {
  @PrimaryGeneratedColumn()
  id: number;
  @Column('text')
  name: string;
  @Column('text')
  email: string;
  @Column('text')
  phoneNumber: string;
  @Column('text')
  password: string;
  @Column('boolean')
  isAdmin: boolean;

  @OneToOne(() => Shop, (shop) => shop.user)
  @JoinColumn()
  shop: Shop;

  constructor(
    name: string,
    email: string,
    phoneNumber: string,
    password: string,
  ) {
    this.name = name;
    this.email = email;
    this.phoneNumber = phoneNumber;
    this.password = password;
  }
}

Shop类代码 #

export class Shop {
  @PrimaryGeneratedColumn()
  id: number;
  @Column()
  name: string;

  @OneToOne(() => User, (user) => user.shop)
  user: User;
  @OneToMany(() => Order, (order) => order.shop)
  orders: Order[];
  @OneToMany(() => Product, (product) => product.shop)
  products: Product[];

  constructor(name: string) {
    this.name = name;
  }
}

UserService查询代码 #

export class UserService {
  constructor(
    @InjectRepository(User)
    private userRepository: Repository<User>,
    private dataSource: DataSource,
  ) {}
  
  findOneByPhoneNumber(phoneNumber: string): Promise<User> {
    return this.userRepository.findOneBy({ phoneNumber });
  }
  ...
}

当前返回结果 #

{
  "name": "test",
  "email": "test@gmail.com",
  "phoneNumber": "+251912345678",
  "password": "$2b$10$Q5FR7cleRkJebMPy.cPWIuPLQrNTMB3kxXWXPiRlFH99U4WfFqyd6",
  "id": 1,
  "isAdmin": false
}

问题原因及解决办法 #

1. Shop类缺少@Entity()装饰器 #

TypeORM无法识别未添加@Entity()的类为数据库实体，导致关联映射完全失效。必须给Shop类补上该装饰器：

@Entity() // 添加这个装饰器
export class Shop {
  @PrimaryGeneratedColumn()
  id: number;
  @Column()
  name: string;

  @OneToOne(() => User, (user) => user.shop)
  user: User;
  @OneToMany(() => Order, (order) => order.shop)
  orders: Order[];
  @OneToMany(() => Product, (product) => product.shop)
  products: Product[];

  constructor(name: string) {
    this.name = name;
  }
}

2. 查询未显式加载关联实体 #

TypeORM默认不会自动加载关联实体，且findOneBy是简化查询方法，不支持关联加载配置。需要改用findOne并指定relations参数，或使用QueryBuilder：

方式一：使用findOne + relations

findOneByPhoneNumber(phoneNumber: string): Promise<User> {
  return this.userRepository.findOne({
    where: { phoneNumber },
    relations: ['shop'], // 指定要预加载的关联实体
  });
}

方式二：使用QueryBuilder（更灵活，适合复杂查询）

findOneByPhoneNumber(phoneNumber: string): Promise<User> {
  return this.userRepository
    .createQueryBuilder('user')
    .leftJoinAndSelect('user.shop', 'shop')
    .where('user.phoneNumber = :phoneNumber', { phoneNumber })
    .getOne();
}

完成以上修改后，查询User时就能同时返回关联的Shop对象了。

内容的提问来源于stack exchange，提问作者Ameen Oumer