fakeDatabase.js

const fakeDatabase = [
    {
        id: 1,
        name: 'Abhay',
        description: 'This is Abhay\'s Database'
    },
    {
        id: 2,
        name: 'Bankimchandra',
        description: 'This is Bankimchandra\'s Database'
    },
    {
        id: 3,
        name: 'chandu',
        description: 'This is chandu\'s Database'
    }
]

module.exports = fakeDatabase;

graphql.js

const graphql = require('graphql');
const fakeDatabase = require('./fakeDatabase');

const fakeDatabaseType = new graphql.GraphQLObjectType({
  name: 'fakeDatabase',
  fields: {
    id: { type: graphql.GraphQLID },
    name: { type: graphql.GraphQLString },
    description: { type: graphql.GraphQLString },
  },
});

var schema = {};
schema.getAllUser = new graphql.GraphQLObjectType({
  name: 'getAllUser',
  fields: {
    data: { 
      type: new graphql.GraphQLList(fakeDatabaseType),
      resolve: () => {
        console.log('from get', fakeDatabase)
        return fakeDatabase;  // here, as our list have elements {} with id, name and description, you need to pass the data from 
                          // the own resolver of type data as it is the parent for fakeDatabaseType
      }
    }
  }
})

const queryType = new graphql.GraphQLObjectType({
  name: 'Query',
  fields: {
    getAllUser: {
      type: schema.getAllUser,
      args: {
      }, resolve: function () {
        console.log('fromm query', fakeDatabase);
        return {}; // just passing empty object, if i have to send the fakeDatabase from here then our data must contain field data,

      }
    }
  }
});
schema.queryTypq1 = new graphql.GraphQLSchema({ query: queryType });


var app = require('express')();
var graphHTTP = require('express-graphql');

app.use('/graphql', graphHTTP({
  schema: schema.queryTypq1,
  graphiql: true
}));

app.listen(4000, () => { console.log('Server is running on port: 4000'); });

Thank You so much, It worked for me. You saved my time. I really want to appreciate york effort and time. Best wishes.

But tell me one thing-
why we are using resolve in schema.getAllUser(){ ..... } ?

/schema.getAllUser = new graphql.GraphQLObjectType({
name: 'getAllUser',
fields: {
data: {
type: new graphql.GraphQLList(fakeDatabaseType),
resolve: () => {
return fakeDatabase; // why here though we are also using resolve() in the resolver method.
}
}
}
})