NestJS Guide
Published in
5 min readJan 1, 2022
Summary
- NestJS Introduction
- NestJS Concepts
- NestJS Coding
- References
1. NestJS Introduction
Hello, nest!
A progressive Node.js framework for building efficient, reliable and scalable server-side applications.
Comapre NestJS vs NodeJS
Types of NodeJS Frameworks
Some statistics
Advantages of using NestJS
- Nest can be scalable thanks to the flexibility of JavaScript and the robustness of TypeScript
- Detailed and well-maintained documentation
- It has active codebase development and maintenance
- It is open source (MIT license)
- Code generation helps to develop applications faster
- Has a quickly growing community
- Follows strict design principles that do a lot of basic development activities for developers
Disadvantages of using NestJS
- It has Angular concepts, so for developers who don’t know Angular, it may be hard to grasp at first, even if you don’t need to know Angular before working with Nest
- Steep learning curve
- The community is small when compared with Express
Who uses NestJS?
- Adidas
- Autodesk
- Neoteric
- Sanofi
3. NestJS Coding
What is NestJS ?
- NodeJS Framework
- Architecture MVC — Model, View, Controller
- Model — Business Layer
- Controller — Persistent Layer
- View — Process HTML, JSON
Advantages NestJS + TypeScript
- Strongly Typed Language
- Visualization of Development Errors
Advantages NestJS + Angular
- Incorporates Modular Ideas and Angular Dependence Injection
Advantages NestJS
- COC — Convention Over Configuration
- Files
- Folders
- Structures of Development
- TypeScript
- Scalable Architecture
- Easy Database Integration
- Microservices Integration
- Support REST API, GraphQL
NestJS Guide GitHub Repository
# sudo npm install -g @nestjs/cli
nest help
nest new nestjs-guide
yarn start
NestJS Architechture Application
- Create an Test Controller
nest g controller test
- Create an test Service
nest g service test- Create an Resource
nest g resource
API REST
NestJS Database Integration
SQL (Sequelize)
This chapter applies only to TypeScript
WARNINGIn this article, you’ll learn how to create a
DatabaseModulebased on the Sequelize package from scratch using custom components. As a consequence, this technique contains a lot of overhead that you can avoid by using the dedicated, out-of-the-box@nestjs/sequelizepackage. To learn more, see here.
Sequelize is a popular Object Relational Mapper (ORM) written in a vanilla JavaScript, but there is a sequelize-typescript TypeScript wrapper which provides a set of decorators and other extras for the base sequelize.
Getting started#
To start the adventure with this library we have to install the following dependencies:
$ npm install --save sequelize sequelize-typescript mysql2
$ npm install --save-dev @types/sequelizeyarn add --save sequelize sequelize-typescript sqlite3 yarn add @nestjs/sequelize yarn add -D @types/sequelizeimport { Sequelize } from 'sequelize-typescript';
import { Cat } from '../cats/cat.entity';
export const databaseProviders = [
{
provide: 'SEQUELIZE',
useFactory: async () => {
const sequelize = new Sequelize({
dialect: 'mysql',
host: 'localhost',
port: 3306,
username: 'root',
password: 'password',
database: 'nest',
});
sequelize.addModels([Cat]);
await sequelize.sync();
return sequelize;
},
},
];
