query 없이 mutation 만작성하면 오류가 난다?

안녕하세요~

복습중 이상한 현상이 발생하여 질문드립니다~

답변 주시면 감사하겠습니다~

질문1.resolver 부분에서

boards() 부분의 주석 부분을 해제해야,

맨아래 3번 오류가 발생하지 않고, 정상 작동 합니다.

Query 없이 Mutation 만작성하면 오류가 발생하는걸까요? 아래 코드와 같이 query 부분을 주석 처리 하면 왜 오류가 나는 걸까요?

질문2.

에러가 내가 작성한 파일의 어떤부분이 잘못됐다고,

알려주는건 없는 걸까요?

아래 에러 코드를 보면 내가 작성한 코드가 아닌

작성하지도 않은 설치 파일같은데서 error 정보가 나오는데, 저기를 열어봐야 할까요?

GraphQLError: Query root type must be provided.

at SchemaValidationContext.reportError (C:\study\00-codecamp-backend\연습장\memo01\node_modules\graphql\type\validate.js:73:7)

1.resolver

import { Args, Mutation, Resolver } from '@nestjs/graphql';
import { BoardsService } from './boards.service';
import { CreateBoardInput } from './dto/create-board.input';
import { Board } from './entities/board.entity';

@Resolver()
export class BoardsResolver {
  constructor(private readonly boardsService: BoardsService) {}

  // @Query(() => String)
  // boards(): string {
  //  return this.boardsService.boards();
  // }

  @Mutation(() => Board)
  createBoard(
    @Args('createBoardInput') createBoardInput: CreateBoardInput, //
  ): Promise<Board> {
    return this.boardsService.create({ createBoardInput });
  }
}

2.service

import { Injectable } from '@nestjs/common';
import { Repository } from 'typeorm';
import { InjectRepository } from '@nestjs/typeorm';
import { IBoardsServiceCreate } from './interfaces/boards-service.interface';
import { Board } from './entities/board.entity';

@Injectable()
export class BoardsService {
  constructor(
    @InjectRepository(Board)
    private readonly boardsRepository: Repository<Board>, //
  ) {}

  // boards() {
  // return 'boards';
  // }

  create({ createBoardInput }: IBoardsServiceCreate): Promise<Board> {
    return this.boardsRepository.save({ ...createBoardInput });
  }
}

3.error

[
  GraphQLError: Query root type must be provided.
      at SchemaValidationContext.reportError (C:\study\00-codecamp-backend\연습장\memo01\node_modules\graphql\type\validate.js:73:7)
      at validateRootTypes (C:\study\00-codecamp-backend\연습장\memo01\node_modules\graphql\type\validate.js:89:13)
      at validateSchema (C:\study\00-codecamp-backend\연습장\memo01\node_modules\graphql\type\validate.js:41:3)
      at graphqlImpl (C:\study\00-codecamp-backend\연습장\memo01\node_modules\graphql\graphql.js:60:63)
      at C:\study\00-codecamp-backend\연습장\memo01\node_modules\graphql\graphql.js:23:43
      at new Promise (<anonymous>)
      at graphql (C:\study\00-codecamp-backend\연습장\memo01\node_modules\graphql\graphql.js:23:10) 
      at GraphQLSchemaFactory.create (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\schema-builder\graphql-schema.factory.js:50:65)
      at GraphQLSchemaBuilder.generateSchema (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\graphql-schema.builder.js:35:52)
      at GraphQLSchemaBuilder.build (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\graphql-schema.builder.js:22:31) {
    path: undefined,
    locations: undefined,
    extensions: [Object: null prototype] {}
  }
]

C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\schema-builder\graphql-schema.factory.js:56
                throw new schema_generation_error_1.SchemaGenerationError(errors);
                      ^
Error: Schema generation error (code-first approach)
    at GraphQLSchemaFactory.create (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\schema-builder\graphql-schema.factory.js:56:23)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at GraphQLSchemaBuilder.generateSchema (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\graphql-schema.builder.js:35:24)
    at GraphQLSchemaBuilder.build (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\graphql-schema.builder.js:22:20)
    at GraphQLFactory.generateSchema (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\graphql.factory.js:27:41)
    at GraphQLModule.onModuleInit (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\graphql\dist\graphql.module.js:109:27)
    at callModuleInitHook (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\core\hooks\on-module-init.hook.js:51:9)
    at NestApplication.callInitHook (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\core\nest-application-context.js:223:13)
    at NestApplication.init (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\core\nest-application.js:100:9)
    at NestApplication.listen (C:\study\00-codecamp-backend\연습장\memo01\node_modules\@nestjs\core\nest-application.js:169:33)