Book Image

Supercharging Node.js Applications with Sequelize

By : Daniel Durante
4 (1)
Book Image

Supercharging Node.js Applications with Sequelize

4 (1)
By: Daniel Durante

Overview of this book

Continuous changes in business requirements can make it difficult for programmers to organize business logic into database models, which turns out to be an expensive operation as changes to the database may result in errors and incongruity within applications. Supercharging Node.js Applications with Sequelize helps you get to grips with Sequelize, a reliable ORM that enables you to alleviate these issues in your database and applications. With Sequelize, you'll no longer need to store information in flat files or memory. This book takes a hands-on approach to implementation and associated methodologies for your database that will have you up and running in no time. You'll learn how to configure Sequelize for your Node.js application properly, develop a better sense of understanding of how this ORM works, and find out how to manage your database from Node.js using Sequelize. Finally, you'll be able to use Sequelize as the database driver for building your application from scratch. By the end of this Node.js book, you'll be able to configure, build, store, retrieve, validate, and associate your data from a database to a Node.js application.
Table of Contents (16 chapters)
1
Part 1 – Installation, Configuration, and the Basics
4
Part 2 – Validating, Customizing, and Associating Your Data
10
Part 3 – Advanced Queries, Using Adapters, and Logging Queries

Order of operations for lifecycle events

Lifecycle events are an important feature when we want to introduce project-specific behaviors/constraints that extend beyond a database engine’s scope. Knowing the lifecycle events is only half of the equation, and the other half consists of knowing when those lifecycle events are triggered.

Suppose we were given the task to offer all of our products for free to employees. The first action could be adding a beforeValidate hook that would set the transaction’s subtotal to 0 if the user was an employee. That’s easy for us, but unfortunately a nightmare for the accounting department. A better approach would be to add an additional item that represents the employee discount, using the beforeValidate or beforeCreate hook.

The real answer in knowing which lifecycle events to use depends on the project’s requirements. From our previous example, some transactions require moving legal tender, which involves charging...