typescript - 为什么在指定类型后我得到 "UnhandledPromiseRejectionWarning: Error: Undefined type error. Make sure are providing an explicit type"？

Question

创建方法运行良好。没有错误。但是我需要一种方法来一次插入大量记录。 这就是我尝试使用 createQueryBuilder 的原因。

它说Undefined type error的原因是什么？我已经将类型定义为 Boolean。

这是我的解析器

@Resolver(() => Vehicle)
export class VehicleResolver {
  constructor(private vehicleService: VehicleService) {}

  @Mutation(() => Vehicle, { name: 'createVehicle' })
  create(@Args('vehicleInput') vehicle: VehicleCreateDTO) {
    return this.vehicleService.create(vehicle);
  }

  @Mutation(() => Boolean, { name: 'createVehicleBulk' })
  async createVehicleBulk(@Args('vehiclesInput') vehicles: [VehicleCreateDTO]) {
    const res = await this.vehicleService
      .createBulk(vehicles)
      .catch((err) => console.log(err));
    if (res) return true;
    else return false;
  }
}

这是我的服务

@Injectable()
export class VehicleService {
  constructor(
    @InjectRepository(Vehicle) private vehicleRepo: Repository<Vehicle>,
  ) {}

  create(vehicle: VehicleCreateDTO): Promise<Vehicle> {
    const vcl = this.vehicleRepo.create(vehicle);
    return this.vehicleRepo.save(vcl);
  }

  async createBulk(vehicles: VehicleCreateDTO[]): Promise<InsertResult> {
    const res = await this.vehicleRepo
      .createQueryBuilder()
      .insert()
      .into('vehicle')
      .values(vehicles)
      .execute();
    return res;
  }
}

我想保存一个 VehicleCreateDTO 类型的对象数组。但是我收到以下错误。

(node:11464) UnhandledPromiseRejectionWarning: Error: Undefined type error. Make sure you are providing an explicit type for the "createBulk" (parameter at index [0]) of the "VehicleResolver" class.
    at Object.reflectTypeFromMetadata (E:\COL\backend\vehicle-service-insert\node_modules\@nestjs\graphql\dist\utils\reflection.utilts.js:15:15) 
    at E:\COL\backend\vehicle-service-insert\node_modules\@nestjs\graphql\dist\decorators\args.decorator.js:17:78
    at E:\COL\backend\vehicle-service-insert\node_modules\@nestjs\graphql\dist\schema-builder\storages\lazy-metadata.storage.js:36:44
    at Array.forEach (<anonymous>)
    at LazyMetadataStorageHost.load (E:\COL\backend\vehicle-service-insert\node_modules\@nestjs\graphql\dist\schema-builder\storages\lazy-metadata.storage.js:36:26)
    at GraphQLSchemaFactory.<anonymous> (E:\COL\backend\vehicle-service-insert\node_modules\@nestjs\graphql\dist\schema-builder\graphql-schema.factory.js:37:57)
    at Generator.next (<anonymous>)
    at E:\COL\backend\vehicle-service-insert\node_modules\@nestjs\graphql\node_modules\tslib\tslib.js:117:75
    at new Promise (<anonymous>)
    at Object.__awaiter (E:\COL\backend\vehicle-service-insert\node_modules\@nestjs\graphql\node_modules\tslib\tslib.js:113:16)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:11464) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
(node:11464) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Answer 1

您的输入类型参数的表示法似乎有误。如果我仔细看的话，错误信息似乎也有误导性

...type for the "createBulk" (parameter at index [0]) of the "VehicleResolver" class...

但在您的解析器中，您只有 createVehicle 和 createVehicleBulk 突变，所以我假设是 createVehicleBulk 突变导致错误。

只是改变:

  @Mutation(() => Boolean, { name: 'createVehicleBulk' })
  async createVehicleBulk(@Args('vehiclesInput') vehicles: [VehicleCreateDTO]) {
    const res = await this.vehicleService
      .createBulk(vehicles)
      .catch((err) => console.log(err));
    if (res) return true;
    else return false;
  }

到

  @Mutation(() => Boolean, { name: 'createVehicleBulk' })
  async createVehicleBulk(@Args({ name: 'vehiclesInput', type: () => [VehicleCreateDTO]}) vehicles: VehicleCreateDTO[]) {
    const res = await this.vehicleService
      .createBulk(vehicles)
      .catch((err) => console.log(err));
    if (res) return true;
    else return false;
  }

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