Graphql does not returns nested query result

Question

I am new to Graphql world. I am using AWS' DynamoDB, Lambda and serverless framework.

I have made simple book Graphql Schema. In book query, I have used author Type.

I have made resolvers, where graphql mutation or query, it will invoke each Lambda functions. For create a Book Item I have made nested mutation, where book can have multiple authors and I successfully create a Book Item. I want to make two diffrent queries. One is Book query where author has type and another is AllAuthors query where it will return all authors and their books. But I am having issue returning an author's type and queries. Both of the queries it returns null like this.

Books queries

All Authors queries

This is my all Graphql schema types:

   enum Genre {
    adventure
    drama
    scifi
  }

  enum Authors {
    AUTHOR
  }
   
   
   // Query Type
   type Query {
    authors(author: Authors): [Author]
    books(book: String): [Book]
  }
   
   // Mutation type
   type Mutation {
    createBook(input: CreateBook!): Book
  }
 
 type Author {
    id: ID!
    authorName: String
    book: [Book]
  }

type Book {
    id: ID!
    name: String
    price: String
    publishingYear: String
    publisher: String
    author: [Author] // Author Type
    description: String
    page: Int
    genre: [Genre] // It's an ENUM 
  } 
  

 
 input CreateBook {
    name: String
    price: String
    publishingYear: String
    publisher: String
    author: [CreateAuthor]
    description: String
    page: Int
    genre: [Genre]
  }

  input CreateAuthor {
    authorName: String!
  }

This is how I create a Book

My DynamoDB image looks like this: .

This is my Book queries Lambda function

import AWS from 'aws-sdk';
import { Book } from '../../generated/schema';

async function books(_: unknown, input: { book: string }): Promise {
  const dynamoDb = new AWS.DynamoDB.DocumentClient();

  const params = {
    TableName: process.env.ITEM_TABLE ? process.env.ITEM_TABLE : '',
    IndexName: 'GSI1',
    KeyConditionExpression: 'GSI1PK = :hkey',
    ExpressionAttributeValues: {
      ':hkey': `${input.book}`,
    },
  };

  const { Items } = await dynamoDb.query(params).promise();

  const Books = Items && Items.map((book: Book) => book); // where author returns null

  return Books;
}

export default books;

This is my authors queries

import AWS from 'aws-sdk';
import { Author, Authors } from '../../generated/schema';

async function authors(
  _: unknown,
  input: { author: Authors }
): Promise {
  const dynamoDb = new AWS.DynamoDB.DocumentClient();

  const params = {
    TableName: process.env.ITEM_TABLE ? process.env.ITEM_TABLE : '',
    KeyConditionExpression: 'PK = :hkey',
    ExpressionAttributeValues: {
      ':hkey': `${input.author}`,
    },
  };

  const { Items } = await dynamoDb.query(params).promise();

  const authors =
    Items &&
    Items.map((d) => {
      console.log({ d });

      d.id = d.PK;
      return d;
    });

  return authors;
}

export default authors;

This is my resolvers

import createBook from './mutations/createBook';
import authors from './queries/authors';
import books from './queries/books';

export default {
  Query: {
    books,
    authors,
  },
  Mutation: {
    createBook,
  },
};

Graphql does not returns nested query result

0 Answers