错误：使用 Nestjs + Graphql + Typeorm 时无法确定 GraphQL 输入类型答案

【问题标题】：Error: Cannot determine a GraphQL input type, while using Nestjs + Graphql + Typeorm错误：使用 Nestjs + Graphql + Typeorm 时无法确定 GraphQL 输入类型
【发布时间】：2021-02-20 12:02:32
【问题描述】：

我正在使用 Nestjs、Graphql 和 Typeorm，而且我是新手。我目前在这个问题上很糟糕。我正在使用@ManyToOne 关系将食物与用户联系起来。但我不断收到错误消息，说我的课程不正确？但我导入它并查看https://docs.nestjs.com/techniques/database#relations 似乎所有语法都是正确的。

看一下ManyToOne下的food.entity，我叫usertest（用于测试目的）

在 food.entity.ts 中

import { ObjectType, Field, ID } from '@nestjs/graphql';
import { Entity, DeepPartial, Column, PrimaryGeneratedColumn, ManyToOne } from 'typeorm';
import { AbstractEntity } from '@shared/entities/abstract.entity';
import { User } from '../user/user.entity';

@ObjectType('Food')
@Entity('foods')
export class Food extends AbstractEntity {
    constructor(input?: DeepPartial<Food>) {
        super(input);
    }

    @Field((type) => ID)
    @PrimaryGeneratedColumn()
    id: number;

    @Field({ nullable: false })
    @Column({ type: 'varchar', length: 255, nullable: false })
    name: string;

    @ManyToOne(() => User, (user) => user.id)
    usertest: User;

}

在 user.entity.ts 中

@ObjectType('User')
@Entity('users')
export class User extends AbstractEntity {
    constructor(input?: DeepPartial<User>) {
        super(input);
    }

    @Field((type) => ID)
    @PrimaryGeneratedColumn('uuid')
    id: string;

    @Field({ nullable: true })
    @Column({ unique: true })
    email: string;

    @Field({ nullable: true })
    @Column({ unique: true })
    phoneNumber: string;

    @Field({ nullable: true })
    @Column({ default: false })
    verified: boolean;

    @Field({ nullable: true })
    @Column({ default: false })
    suspended: boolean;

    @Field({ nullable: true })
    @Column({ length: 255, nullable: true })
    name?: string;

    @Field({ nullable: true })
    @Column({ length: 120, nullable: true })
    firstName?: string;

    @Field({ nullable: true })
    @Column({ length: 120, nullable: true })
    lastName?: string;

    @Field((type) => UserRole, { nullable: true })
    @Column({ type: 'enum', enum: UserRole })
    role: UserRole;

    @Column()
    password: string;
}

我收到的错误：

(node:58449) UnhandledPromiseRejectionWarning: Error: Cannot determine a GraphQL input type for the "usertest". Make sure your class is decorated with an appropriate decorator.
    at InputTypeFactory.create (/Users/ivan/Documents/Programming/Baker/api-core/node_modules/@nestjs/graphql/dist/schema-builder/factories/input-type.factory.js:19:23)
    at /Users/ivan/Documents/Programming/Baker/api-core/node_modules/@nestjs/graphql/dist/schema-builder/factories/input-type-definition.factory.js:44:52
    at Array.forEach (<anonymous>)
    at /Users/ivan/Documents/Programming/Baker/api-core/node_modules/@nestjs/graphql/dist/schema-builder/factories/input-type-definition.factory.js:42:33
    at resolveThunk (/Users/ivan/Documents/Programming/Baker/api-core/node_modules/graphql/type/definition.js:478:40)
    at defineInputFieldMap (/Users/ivan/Documents/Programming/Baker/api-core/node_modules/graphql/type/definition.js:1203:18)
    at GraphQLInputObjectType.getFields (/Users/ivan/Documents/Programming/Baker/api-core/node_modules/graphql/type/definition.js:1151:27)
    at TypeFieldsAccessor.extractFromInputType (/Users/ivan/Documents/Programming/Baker/api-core/node_modules/@nestjs/graphql/dist/schema-builder/services/type-fields.accessor.js:9:35)
    at /Users/ivan/Documents/Programming/Baker/api-core/node_modules/@nestjs/graphql/dist/schema-builder/factories/input-type-definition.factory.js:56:66
    at resolveThunk (/Users/ivan/Documents/Programming/Baker/api-core/node_modules/graphql/type/definition.js:478:40)

【问题讨论】：

错误是关于 graphql 特定的“输入类型”，阅读文档
@xadm 输入类型是一个名为 User 的类。我仍然看不到问题。如果你能引导我走向正确的道路，可以吗？
@InputType() 在哪里？编译器声称这是一个问题

标签： node.js typescript graphql nestjs typeorm

【解决方案1】：

缺少@InputType()。

像这样

@ObjectType('User')
@InputType('UserInput')
@Entity('users')

我不完全确定这是正确的方法还是正确的做法，但它对我有用。

【讨论】：

【解决方案2】：

如果您想将对象作为输入类型属性传递，请使用 GraphQLJSONObject

 @Field(() => GraphQLJSONObject, { nullable: true })
 employee: UserObject;

【讨论】：