How do I practice NestJs? — NestJs + GraphQL + TypeORM + MongoDB

“ I wrote this topic to record my own self-learning journey as well as share anybody about them. ”

Built with NestJs, GraphQL, TypeORM, MongoDB

1. Requirement

• NestJs
• GraphQL
• MongoDB

2. Table of contents

• Initialize NestJs project
• Create folder User
• Demo query “Hello world” with GraphQL
• TypeORM connect MongoDB
• CRUD with object User

3. Practice

A progressive Node.js framework for building efficient, reliable and scalable server-side applications.

NestJS — A progressive Node.js web framework

Setup

// Setting up a new project is quite simple with the Nest CLI
$ npm i -g @nestjs/cli
// or
$ yarn add global @nestjs/cli
// Create new nest project
$ nest new project-name

Run It!

// Development
$ npm run start
// or
$ yarn start
// Watch mode
$ npm run start:dev
// or
$ yarn start:dev

Logger

GraphQL

Next, we will integrate GraphQL with nest via here

First of all, we must config tsconfig.json

Second, we need to install the required packages:

$ npm i --save @nestjs/graphql apollo-server-express graphql-tools graphql
$ yarn add @nestjs/graphql apollo-server-express graphql-tools graphql

Nest offers two ways of building GraphQL applications, the schema first and the code first respectively.

In this example, I will use schema first

I use Nest CLI via here to generate code.

$ nest g mo user
$ nest g r user
$ nest g s user

Next, I touch user.graphql in user

$ touch src/user/user.graphql

Finally that we have a new folder structure like that.

Folder structure

Demo query “Hello world”

We declare query hello below

Yeah that’s working

TypeORM connect MongoDB

Base on nest via here, we have to install all required dependencies:

$ npm i --save @nestjs/typeorm typeorm @types/mongodb mongodb
// OR
$ yarn add @nestjs/typeorm typeorm @types/mongodb mongodb

CRUD with object User

Read more TypeORM entity via here

Back to a user folder, we touch 2 files user.input.ts & user.entity.ts

$ touch src/user/user.entity.ts
$ touch src/user/user.input.ts

Create User, UserInput, users, createUser in user.graphql

Then we provide user entity for user.module.ts

At user.resolver.ts, we will inject user.service.ts and declare query, mutation

Similar, we will inject the user entity in user.service.ts

we will use uuid v4 for user._id

$ npm i uuid

If you want to perform updates and deletions, you can refer to the source below

chnirt/chnirt-demo-nest-typeorm-mongodb

Thank you for reading this
I am Chnirt and I will see you again in next episode.