Phi Nguyen phibn

'Include' in Sequelize: The One Confusing Query That You Should Memorize

When querying your database in Sequelize, you'll often want data associated with a particular model which isn't in the model's table directly. This data is usually typically associated through join tables (e.g. a 'hasMany' or 'belongsToMany' association), or a foreign key (e.g. a 'hasOne' or 'belongsTo' association).

When you query, you'll receive just the rows you've looked for. With eager loading, you'll also get any associated data. For some reason, I can never remember the proper way to do eager loading when writing my Sequelize queries. I've seen others struggle with the same thing.

Eager loading is confusing because the 'include' that is uses has unfamiliar fields is set in an array rather than just an object.

So let's go through the one query that's worth memorizing to handle your eager loading.

The Basic Query

React lifecycle cheatsheet

Method	Side effects¹	State updates²	Example uses
Mounting
`componentWillMount`		✓	Constructor equivalent for `createClass`
`render`			Create and return element(s)
`componentDidMount`	✓	✓	DOM manipulations, network requests, etc.
Updating
`componentWillReceiveProps`		✓	Update `state` based on changed `props`

The Ultimate Unit Testing Cheat-sheet

Sinon Chai
Chai
Sinon


	import * as mongoose from 'mongoose';

	export let Schema = mongoose.Schema;
	export let ObjectId = mongoose.Schema.Types.ObjectId;
	export let Mixed = mongoose.Schema.Types.Mixed;

	export interface IHeroModel extends mongoose.Document {
	name: string;
	power: string;