解析一个冲突解决程序中的所有字段v.s.解析每个冲突解决程序中的字段

这是我的 typeDefs :

const typeDefs: string = `
  type Book {
    id: ID!
    title: String
    authorId: ID!
    author: User
  }

  type User {
    id: ID!
    name: String
  }

  type Query {
    books: [Book]!
  }
`;

export { typeDefs };

resolvers :

import { IResolvers } from 'graphql-tools';
import { IBook } from './db';

const resolvers1: IResolvers = {
  Query: {
    books: (_, args, { db }): Promise<IBook[]> => {
      return db.books.map(book => {
        book.author = db.users.find(user => book.authorId === user.id);
        return book;
      });
    }
  }
};

const resolvers2: IResolvers = {
  Query: {
    books: (_, args, { db }): Promise<IBook[]> => {
      return db.books;
    }
  },
  Book: {
    author: (book, args, { db }) => {
      return db.users.find(user => book.authorId === user.id);
    }
  }
};

export { resolvers1, resolvers2 };

内 resolvers1 ,它解析 Book . (添加) author 字段到 book )

内 resolvers2 ,它解析 书 在独立分解器中。

我发现两者 resovlers1 和 解决方案2 工作很好。我可以得到这样的正确回答:

{
  "data": {
    "books": [
      {
        "id": "02wDZbBuMi",
        "title": "Ea repellendus",
        "authorId": "hhP2TtobM",
        "author": {
          "id": "hhP2TtobM",
          "name": "Mrs. Destiney Kerluke"
        }
      },
      {
        "id": "tC3uPfKfUZ",
        "title": "Consectetur fugit",
        "authorId": "k9IHZAtld8",
        "author": {
          "id": "k9IHZAtld8",
          "name": "Mr. Rene Heidenreich"
        }
      }
    ]
  }
}

他们之间有什么区别?这两种方法正确吗?如果不是,为什么?