# NestJS Guide Summary 1. NestJS Introduction 2. NestJS Concepts 3. NestJS Coding 4. References ### 1\. NestJS Introduction ### Hello, nest! #### A progressive Node.js framework for building efficient, reliable and scalable server-side applications. ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833247887/Ro98bzUaS.png) [https://nestjs.com/](https://nestjs.com/) [**GitHub - nestjs/nest: A progressive Node.js framework for building efficient, scalable, and…** *A progressive Node.js framework for building efficient, scalable, and enterprise-grade server-side applications on top…*github.com](https://github.com/nestjs/nest "https://github.com/nestjs/nest")[](https://github.com/nestjs/nest) ### Comapre NestJS vs NodeJS ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833249416/Y95rF0-yo.jpeg) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833250755/Fej2Zo5eg.png) ### Types of NodeJS Frameworks ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833252067/p3g1Be5QK.png) NodeJS Frameworks ### Some statistics ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833253398/tAxEKZAbS.png) ### 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 ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833254751/hCzU3B9jB.jpeg) ### 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 [**GitHub - Software-Engineering-2030/NestJS-Guide: NestJS Guide Software Engenieering** *A progressive Node.js framework for building efficient and scalable server-side applications. Nest framework TypeScript…*github.com](https://github.com/Software-Engineering-2030/NestJS-Guide "https://github.com/Software-Engineering-2030/NestJS-Guide")[](https://github.com/Software-Engineering-2030/NestJS-Guide) \# sudo npm install -g @nestjs/cli nest help ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833256379/11HJftYoI.png) ``` nest new nestjs-guide ``` ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833257964/hs3B1zUMj.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833259492/pkSLU9hWQ.png) yarn start ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833261018/3_bkCN0cY.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833262640/YYqbqnMxB.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833264039/3bBljB0RLx.png) ### NestJS Architechture Application ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833265395/sIL0ibPhB7.png) * Create an Test Controller nest g controller test ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833266869/z3J55d_7Q.png) nest g controller test * Create an test Service nest g service test * Create an Resource nest g resource ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833268283/scSQCRhwqFp.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833269496/4ewNsgOSh8.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833271400/krvEdKjCtc.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833273188/6-M6D8e26.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833276056/RNPXv4x7Z.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833277493/IkWwPMUrY.png) ### API REST ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833278929/t1BKupDB9.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833280278/k14jW3kksv.png) ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833281677/0AUOFJOUB.png) API Resource Name ### NestJS Database Integration ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833283043/dd2C4nDz1.png) ### SQL (Sequelize) This chapter applies only to TypeScript > ***WARNING****In this article, you’ll learn how to create a* `*DatabaseModule*` *based 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/sequelize*` *package. To learn more, see* [*here*](https://docs.nestjs.com/techniques/database#sequelize-integration)*.* [Sequelize](https://github.com/sequelize/sequelize) is a popular Object Relational Mapper (ORM) written in a vanilla JavaScript, but there is a [sequelize-typescript](https://github.com/RobinBuschmann/sequelize-typescript) TypeScript wrapper which provides a set of decorators and other extras for the base sequelize. #### Getting started[#](https://docs.nestjs.com/recipes/sql-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/sequelize ``` ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833284321/DNXN-TxKS.png) ``` yarn add --save sequelize sequelize-typescript sqlite3 ``` ``` yarn add @nestjs/sequelize ``` ``` yarn add -D @types/sequelize ``` ``` `import { 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; }, }, ];` ``` ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1662833285709/ZfXN0ka0h.png) [**Sequelize** *Sequelize is a promise-based Node.js ORM for Postgres, MySQL, MariaDB, SQLite and Microsoft SQL Server. It features…*sequelize.org](https://sequelize.org/ "https://sequelize.org/")[](https://sequelize.org/) ### 4\. References * [https://nestjs.com/](https://nestjs.com/) * [https://blog.logrocket.com/comparing-top-node-js-frameworks-frontend-developers/](https://blog.logrocket.com/comparing-top-node-js-frameworks-frontend-developers/)