Nest错误:无法确定getProducts的GraphQL输出类型

Question

当我试图从解析程序返回自定义dto时，会出现此错误。(node:28156) UnhandledPromiseRejectionWarning: Error: Cannot determine GraphQL output type for getProducts

以下是我的代码。

product.entity.ts

import {
Entity,
Column,
PrimaryGeneratedColumn,
BaseEntity,
BeforeInsert,
} from 'typeorm';
import { ObjectType, Field, ID, Float, Int } from '@nestjs/graphql';
@ObjectType()
@Entity()
export class Product extends BaseEntity {
@Field(() => ID)
@PrimaryGeneratedColumn('uuid')
id: string;
@Column({ default: '', select: false })
ratingsString: string;
@Field(() => [Int])
ratings;
@BeforeInsert()
setRatingsString() {
this.ratingsString = this.ratings.join(',');
}
}

product.resolver.ts

import { Resolver, Query, Args, ResolveField, Int, Parent } from '@nestjs/graphql';
import { Product } from './product.entity';
import { ProductService } from './product.service';
@Resolver(() => Product)
export class ProductResolver {
constructor(private productService: ProductService) {}
@Query(() => GetProductDto, { name: 'products' })
async getProducts(@Args() page: number) {
return this.productService.getProducts(page);
}
}

产品.服务.ts

import { Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Product } from './product.entity';
import { GetProductDto } from './product.dto';
@Injectable()
export class ProductService {
constructor(
@InjectRepository(Product) private productRepo: Repository<Product>,
) {}
async getProducts(page: number): Promise<GetProductDto> {
const MAX_PRODUCT_PER_PAGE = 20;
const start = page < 1 ? 1 : page;
const [products, productsCount] = await this.productRepo.findAndCount({
skip: (start - 1) * MAX_PRODUCT_PER_PAGE,
take: MAX_PRODUCT_PER_PAGE,
});
const productList = products.map(product => {
product.ratings = product.ratingsString.split(',').map(Number);
delete product.ratingsString;
return product;
});
return {
products: productList,
total: productsCount,
};
}
}

产品.dto.ts

import { Field, Int, InputType } from '@nestjs/graphql';
import { Product } from './product.entity';
@InputType()
export class GetProductDto {
@Field(() => [Product])
products: Product[];
@Field(() => Int)
total: number;
}

这里的期望是，当我调用products查询时，我将收到一个包含products和total的对象。Whee产品将是我的一系列产品。我做错了什么？

Answer 1

原来我只需要向Args提供一个参数。

@Query(() => GetProductDto, { name: 'products' })
async getProducts(@Args('arg_the_client_will_it_with') page: number) {
return this.productService.getProducts(page);
}