Muiruriscode / GraphQl-express-server

Book App Server

The project involved the creation of a server for the Book App Application. The server enables acces to data using graphQL. The server uses mongoose to connect to MongoDB atlas to store data.

Features

• [] Connect to MongoDB database using mongoose
• [] Access of Author information using the author query
• [] Access Book information through the books query
• [] Add a book to the database using the addBook mutation
• [] Add author to the database using the AddAuthor mutation

Dependencies

• Express.js
• Mongoose.js
• GraphQl
• Express-graphql

Installation

npm install express mongoose graphql express-graphql concurrently
npm install -D nodemon

Concurrently enables the client to a access the data from the server easily. It runs the server and the client concurrently without the cors issue.

GaphQl Types

Book Type

Defines the data types for the book and the relationhip with the author resolve function

const BookType = new GraphQLObjectType({
  name: 'Book',
  fields: () => ({
    id: { type: GraphQLID },
    name: { type: GraphQLString },
    genre: { type: GraphQLString },
    author: {
      type: AuthorType,
      resolve(parent, args) {
        return Author.findById(parent.authorId)
      },
    },
  }),
})

Author Type

Defines the data types for the author and the relationhip with the book resolve function

const AuthorType = new GraphQLObjectType({
  name: 'Author',
  fields: () => ({
    id: { type: GraphQLID },
    name: { type: GraphQLString },
    age: { type: GraphQLInt },
    books: {
      type: new GraphQLList(BookType),
      resolve(parent, args) {
        return Book.find({ authorId: parent.id })
      },
    },
  }),
})

Queries

Book Query

The query to be used to access a book from the database

Book: {
      type: BookType,
      args: { id: { type: GraphQLID } },
      resolve(parent, args) {
        return Book.findById(args.id);
      },
    },

The query to access all books from the database

   Books: {
      type: new GraphQLList(BookType),
      resolve(parent, args) {
        return Book.find({});
      },
    },

Author Query

The query to be used to access an Author from the database

Author: {
      type: AuthorType,
      args: { id: { type: GraphQLID } },
      resolve(parent, args) {
        return Author.findById(args.id);
      },
    },

The Query to acces all authors from the dtabase

Authors: {
      type: new GraphQLList(AuthorType),
      resolve(parent, args) {
        return Author.find({});
      },
    },

Mutations

Mutations are used to modify data in the database

Book Mutation

Add a book to the database

addBook: {
      type: BookType,
      args: {
        name: { type: new GraphQLNonNull(GraphQLString) },
        genre: { type: new GraphQLNonNull(GraphQLString) },
        authorId: { type: new GraphQLNonNull(GraphQLID) },
      },
      resolve(parent, args) {
        let book = new Book({
          name: args.name,
          genre: args.genre,
          authorId: args.authorId,
        });
        return book.save();
      },
    },
    ```

Author Mutation

Add an author to the database

addAuthor: {
      type: AuthorType,
      args: {
        name: { type: new GraphQLNonNull(GraphQLString) },
        age: { type: new GraphQLNonNull(GraphQLInt) },
      },
      resolve(parent, args) {
        let author = new Author({
          name: args.name,
          age: args.age,
        });
        return author.save();
      },
    },