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

Using validations as constraints

There are certain validations that Sequelize will use as both a validation and a constraint. These parameters are configurable in the attribute’s options as a sibling to the validate parameters. Constraints are defined and guarded by the database, whereas a validation will be handled by Sequelize and the Node.js runtime exclusively. Here is a list of constraints made available from Sequelize.

allowNull

The allowNull option will determine whether to apply NOT NULL to the definitions of columns for the database. The default value is true, which will allow columns to have a value of null. There are a couple of caveats to keep in mind when using validations with the allowNull constraint:

  • If the allowNull parameter is set to false and the attribute’s value is null, then the custom validations will not run. Instead, a ValidationError will be returned without making a request to the database.
  • If the allowNull parameter is set...