Sequelize ORM setup in Express - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Sequelize in the context of Express applications?

Sequelize is an Object-Relational Mapping (ORM) library for Node.js that helps you interact with SQL databases using JavaScript objects instead of writing raw SQL queries.

beginner

Which command installs Sequelize and its required database driver for PostgreSQL?

You run npm install sequelize pg pg-hstore to install Sequelize and the PostgreSQL driver.

beginner

What is the purpose of the Sequelize constructor in setup?

The Sequelize constructor creates a new Sequelize instance that connects your app to the database using credentials like database name, username, password, host, and dialect.

beginner

How do you define a simple model in Sequelize?

You use sequelize.define('ModelName', { attributeName: DataTypes.TYPE, ... }) to create a model representing a table in the database.

beginner

Why is it important to call sequelize.sync() during setup?

Calling sequelize.sync() creates the tables in the database if they don't exist yet, based on your model definitions. It keeps your database structure in sync with your code.

Which of these is NOT needed to create a Sequelize connection?

A Database name

B Port number

C Username

D Password

Port number is optional because Sequelize uses default ports for each database dialect unless specified.

What does the dialect option specify in Sequelize?

A The frontend framework used

B The version of Node.js

C The type of database you are connecting to

D The port number for the server

The dialect tells Sequelize which database type (like 'postgres', 'mysql', 'sqlite') it should communicate with.

Which method creates tables in the database based on your models?

A sequelize.sync()

B sequelize.build()

C sequelize.create()

D sequelize.connect()

sequelize.sync() creates tables if they don't exist, matching your model definitions.

How do you define a model attribute for a string in Sequelize?

A attribute: Sequelize.STRING

B attribute: 'string'

C attribute: String

D attribute: sequelize.string

Sequelize provides data types like Sequelize.STRING to define model attributes.

Which package do you install to use Sequelize with MySQL?

A mssql

B pg

C sqlite3

D mysql2

For MySQL, you install mysql2 as the database driver alongside Sequelize.

Explain the steps to set up Sequelize in an Express app from installation to syncing models.

Think about what you need to connect, define, and prepare your database tables.

Describe how Sequelize helps you avoid writing raw SQL queries in your Express app.

Focus on how Sequelize acts as a bridge between JavaScript and the database.