schema.js

//*
import {resolver} from 'graphql-sequelize';
import Sequelize from 'sequelize';
import {
  GraphQLInt,
  GraphQLList,
  GraphQLObjectType,
  GraphQLNonNull,
  GraphQLSchema,
  GraphQLString,
} from 'graphql';

import {
  connectionArgs,
  connectionDefinitions,
  connectionFromArray,
  fromGlobalId,
  globalIdField,
  mutationWithClientMutationId,
  nodeDefinitions,
} from 'graphql-relay';
//*
// sequelize config
let sequelize = new Sequelize('database', 'username', 'password', {
  dialect: 'sqlite',
  storage: __dirname + '/database.sqlite'
})

// model user
let User = sequelize.define('user', {
  name: Sequelize.STRING
});
// model Task
let Task = sequelize.define('task', {
  title: Sequelize.STRING
});

User.Tasks = User.hasMany(Task, {as: 'tasks'});


// sequelize.sync();
// grapql

let taskType = new GraphQLObjectType({
  name: 'Task',
  description: 'A task',
  fields: {
    id: {
      type: new GraphQLNonNull(GraphQLInt),
      description: 'The id of the task.',
    },
    title: {
      type: GraphQLString,
      description: 'The title of the task.',
    }
  }
});

let userType = new GraphQLObjectType({
  name: 'User',
  description: 'A user',
  fields: {
    id: {
      type: new GraphQLNonNull(GraphQLInt),
      description: 'The id of the user.',
    },
    name: {
      type: GraphQLString,
      description: 'The name of the user.',
    },
    tasks: {
      type: new GraphQLList(taskType),
      resolve: resolver(User.Tasks, {
        separate: true // load seperately, disables auto including - default: false
      })
    }
  }
});


let mutation = new GraphQLObjectType({
  name: 'RootMutationType',
  fields: {
    updateUser: {
        type: userType,
        args: {
          id: {
            name: 'id',
            type: new GraphQLNonNull(GraphQLString)
          },
          name: {
            name: 'name',
            type: GraphQLString
          }
        },
        resolve: function (obj, {id, name}) {
          User.update({name: name}, {where: { id: id }});

          return User.findById(id);
        }
    }
  }
});




var viewerType = new GraphQLObjectType({
  name: 'viewer',
  fields: () => ({
    users: {
      args: {

      },
      type: new GraphQLList(userType),
      resolve: resolver(User)
    },
  }),
});

var a = function () {
  return {users: resolver(User)};
}
export default new GraphQLSchema({
  query: new GraphQLObjectType({
    name: 'query',
    fields: () => ({
      viewer: {
        type: viewerType,
        resolve: a,
      },
    }),
  }),
});