dynogels/examples/globalSecondaryIndexes.js

DynamoDB data mapper

'use strict';

const dynogels = require('../index');
const _ = require('lodash');
const util = require('util');
const AWS = dynogels.AWS;
const Joi = require('joi');
const async = require('async');

// AWS.config.loadFromPath(`${process.env.HOME}/.ec2/credentials.json`);

// http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSI.html

AWS.config.update({ region: 'us-east-1' });

const GameScore = dynogels.define('example-global-index', {
  hashKey: 'userId',
  rangeKey: 'gameTitle',
  schema: {
    userId: Joi.string(),
    gameTitle: Joi.string(),
    topScore: Joi.number(),
    topScoreDateTime: Joi.date(),
    wins: Joi.number(),
    losses: Joi.number()
  },
  indexes: [{
    hashKey: 'gameTitle',
    rangeKey: 'topScore',
    name: 'GameTitleIndex',
    type: 'global',
    projection: { NonKeyAttributes: ['wins'], ProjectionType: 'INCLUDE' }
  },
  { hashKey: 'gameTitle', rangeKey: 'losses', name: 'GameLosersIndex', type: 'global' }
  ]
});

const data = [
  { userId: '101', gameTitle: 'Galaxy Invaders', topScore: 5842, wins: 10, losses: 5, topScoreDateTime: new Date(2012, 1, 3, 8, 30) },
  { userId: '101', gameTitle: 'Meteor Blasters', topScore: 1000, wins: 12, losses: 3, topScoreDateTime: new Date(2013, 1, 3, 8, 30) },
  { userId: '101', gameTitle: 'Starship X', topScore: 24, wins: 4, losses: 9 },

  { userId: '102', gameTitle: 'Alien Adventure', topScore: 192, wins: 32, losses: 192 },
  { userId: '102', gameTitle: 'Galaxy Invaders', topScore: 0, wins: 0, losses: 5 },

  { userId: '103', gameTitle: 'Attack Ship', topScore: 3, wins: 1, losses: 8 },
  { userId: '103', gameTitle: 'Galaxy Invaders', topScore: 2317, wins: 40, losses: 3 },
  { userId: '103', gameTitle: 'Meteor Blasters', topScore: 723, wins: 22, losses: 12 },
  { userId: '103', gameTitle: 'Starship X', topScore: 42, wins: 4, losses: 19 },
];

const loadSeedData = callback => {
  callback = callback || _.noop;

  async.each(data, (attrs, callback) => {
    GameScore.create(attrs, callback);
  }, callback);
};

async.series([
  async.apply(dynogels.createTables.bind(dynogels)),
  loadSeedData
], err => {
  if (err) {
    console.log('error', err);
    process.exit(1);
  }

  // Perform query against global secondary index
  GameScore
  .query('Galaxy Invaders')
  .usingIndex('GameTitleIndex')
  .where('topScore').gt(0)
  .descending()
  .exec((err, data) => {
    if (err) {
      console.log(err);
    } else {
      console.log('Found', data.Count, 'items');
      console.log(util.inspect(_.pluck(data.Items, 'attrs')));
    }
  });
});